adding tagging on a document type that already has it throws an exception

To reproduce:

• Tick the checkbox next to "doctype1" and click "Add tagging"
• Then tick another checkbox next to another doc type and click "Add tagging" again

You now get a big stacktrace about the fact that doctype1 already has tagging configured:

[INFO] [talledLocalContainer] 15.04.2015 13:14:32 ERROR http-nio-8080-exec-5 [TaggingResource.addDocuments:124] Error adding tagging documents field
[INFO] [talledLocalContainer] javax.jcr.ItemExistsException: Node with the same UUID exists:node /hippo:namespaces/myhippoproject/author/editor:templates/default/tags
[INFO] [talledLocalContainer] at org.apache.jackrabbit.core.xml.SessionImporter.startNode(SessionImporter.java:380)
[INFO] [talledLocalContainer] at org.apache.jackrabbit.core.xml.SysViewImportHandler.processNode(SysViewImportHandler.java:93)
[INFO] [talledLocalContainer] at org.apache.jackrabbit.core.xml.SysViewImportHandler.startElement(SysViewImportHandler.java:134)
[INFO] [talledLocalContainer] at org.apache.jackrabbit.core.xml.ImportHandler.startElement(ImportHandler.java:175)
[INFO] [talledLocalContainer] at org.apache.jackrabbit.commons.xml.DefaultContentHandler.startElement(DefaultContentHandler.java:161)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:509)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:379)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2786)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:117)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:649)
[INFO] [talledLocalContainer] at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(SAXParserImpl.java:333)
[INFO] [talledLocalContainer] at org.apache.jackrabbit.commons.xml.ParsingContentHandler.parse(ParsingContentHandler.java:62)
[INFO] [talledLocalContainer] at org.apache.jackrabbit.commons.AbstractSession.importXML(AbstractSession.java:344)
[INFO] [talledLocalContainer] at org.hippoecm.repository.decorating.SessionDecorator.importXML(SessionDecorator.java:231)
[INFO] [talledLocalContainer] at org.hippoecm.repository.impl.SessionDecorator.importXML(SessionDecorator.java:218)
[INFO] [talledLocalContainer] at org.onehippo.cms7.essentials.plugins.tagging.TaggingResource.addDocuments(TaggingResource.java:104)
[INFO] [talledLocalContainer] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[INFO] [talledLocalContainer] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[INFO] [talledLocalContainer] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[INFO] [talledLocalContainer] at java.lang.reflect.Method.invoke(Method.java:483)
[INFO] [talledLocalContainer] at org.apache.cxf.service.invoker.AbstractInvoker.performInvocation(AbstractInvoker.java:181)
[INFO] [talledLocalContainer] at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:97)
[INFO] [talledLocalContainer] at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:200)
[INFO] [talledLocalContainer] at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:99)
[INFO] [talledLocalContainer] at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:59)
[INFO] [talledLocalContainer] at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:96)
[INFO] [talledLocalContainer] at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:307)
[INFO] [talledLocalContainer] at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
[INFO] [talledLocalContainer] at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:251)
[INFO] [talledLocalContainer] at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:223)
[INFO] [talledLocalContainer] at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:197)
[INFO] [talledLocalContainer] at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:149)
[INFO] [talledLocalContainer] at org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:171)
[INFO] [talledLocalContainer] at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:290)
[INFO] [talledLocalContainer] at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doPost(AbstractHTTPServlet.java:209)
[INFO] [talledLocalContainer] at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
[INFO] [talledLocalContainer] at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:265)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
[INFO] [talledLocalContainer] at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
[INFO] [talledLocalContainer] at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
[INFO] [talledLocalContainer] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
[INFO] [talledLocalContainer] at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
[INFO] [talledLocalContainer] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
[INFO] [talledLocalContainer] at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
[INFO] [talledLocalContainer] at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
[INFO] [talledLocalContainer] at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
[INFO] [talledLocalContainer] at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1517)
[INFO] [talledLocalContainer] at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1474)
[INFO] [talledLocalContainer] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
[INFO] [talledLocalContainer] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
[INFO] [talledLocalContainer] at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
[INFO] [talledLocalContainer] at java.lang.Thread.run(Thread.java:745)