'Classic' CMS: Remove code duplication

In order to support the two CMS flavors the following classes have been duplicated:

hippo-ecm$ find . -name New*.java
./addon/builtin/frontend/src/main/java/org/hippoecm/frontend/plugins/standardworkflow/NewAbstractFolderWorkflowPlugin.java
./addon/builtin/frontend/src/main/java/org/hippoecm/frontend/plugins/standardworkflow/NewRemodelWorkflowPlugin.java
./addon/builtin/frontend/src/main/java/org/hippoecm/frontend/plugins/standardworkflow/remodel/NewRemodelDialog.java
./addon/builtin/frontend/src/main/java/org/hippoecm/frontend/plugins/standardworkflow/dialogs/NewCreateTypeDialog.java
./addon/builtin/frontend/src/main/java/org/hippoecm/frontend/plugins/standardworkflow/dialogs/NewNamespaceDialog.java
./addon/builtin/frontend/src/main/java/org/hippoecm/frontend/plugins/standardworkflow/dialogs/NewCopyModelDialog.java
./addon/builtin/frontend/src/main/java/org/hippoecm/frontend/plugins/standardworkflow/NewOrderableFolderWorkflowPlugin.java
./addon/builtin/frontend/src/main/java/org/hippoecm/frontend/plugins/standardworkflow/NewFolderWorkflowPlugin.java
./addon/builtin/frontend/src/main/java/org/hippoecm/frontend/plugins/standardworkflow/NewFolderWorkflowExtendedDialog.java
./addon/builtin/frontend/src/main/java/org/hippoecm/frontend/plugins/standardworkflow/NewFolderWorkflowDialog.java
./addon/builtin/frontend/src/main/java/org/hippoecm/frontend/plugins/standardworkflow/NewNamespaceWorkflowPlugin.java
./addon/cms/browse/src/main/java/org/hippoecm/frontend/plugins/cms/browse/list/NewDocumentListingPlugin.java