Support compability to changed interface of activeobjects-plugin affecting AoEventsListener

Confluence 5.7 has a dependency to activeobjects-plugin-0.28.12.jar which changed its interface of ActiveObjectsModuleMetaData to throw two additional exceptions in com.atlassian.activeobjects.external.ActiveObjectsModuleMetaData.awaitInitialization.
Implementation of a solution to support the old and the new versions of activeobjects-plugin.jar for de.smartics.projectdoc.atlassian.confluence.AoEventsListener.