JBIDE-15321 ConcurrentModificationException in KbBuilder

Required synchronization is added.
JBIDE-15325 NullPointerException in ExternalizeStringsUtils in jsf facelets editor

Added check on null
JBIDE-15336 Action "Externalize all strings..." does not work at all

Deleted Action "Externalize all strings..."
[JBIDE-13795] Incorrect URL for JBoss Jira on readmes
JBIDE-11319: Url for Eclipse-SourceReferences