Removed junit declaration from .gwt.xml and added a *Dev.gwt.xml
This is for future support of super dev mode. 
Removed current GwtTest cases which were not adding much value, and
definitely didn't need to run in the scope of a GwtTest case.
Updated web.xml to remove unnecessary junit servlets.
core-5087 add info icon to images
core-4609 fix preferences dialog default output folder validation issue
core-5060 add link to idrop download wiki page
remove unused import.
externalize strings
Merge branch 'master' into STABLE