In the logged human readable messages, include the priority of the message

Currently I see for example being logged

Failed to reload web files from '[/home/aschrijvers/hippo-projects/ARCHE/trunk/website/target/gettingstarted/bootstrap/webfiles/src/main/resources/site/ftl-copy/base/main/list/list-title.ftl]' : 'org.onehippo.cms7.services.webfiles.WebFileException: Cannot import web files at '/webfiles/site/ftl-copy/base/main/list': no such node', resetting session and trying to reimport whole bundle(s)

As a user/developer I can't possibly know whether the above message is an error, warn or info message. I am triggered by for example 'failed', but after that do not know whether it in the end is just INFO (which it happens to be!) or whether it is real issue (WARN)