OO-615: implements a simple filter to allow CORS (cross origin resource sharing) but restricted to the rest api

OO-592: remove tx manager annotations scanner, move configurations in resources/serviceconfig to java/... where they are needed, use import instead of the *Context.xml which allow deployment on weblogic and some others small fixes

OO-592: break direct dependency to UserDataDeletable and DeletableGroupData interfaces, remove unused spring configuration files...

OO-449: first part of the implementation: remove smack libraries, refactor controller and unify them, implements messaging across the OpenOLAT event bus, implements administration part to enable chat...