WIKI-588 [Jboss] Error when selecting Link, Image, Macro in add wiki at rich text mode

Fix description: Using userID instead of sessionID to store shared data in org.exoplatform.wiki.service.impl.SessionManager. Backport WIKI 566

Conflicts:
	wiki-webui/src/main/java/org/exoplatform/wiki/webui/WikiRemoteServiceServlet.java