Fixing null pointer issue when detaching the widget on editor close.
Fixing index out of bounds issue when adding new sub attributes during
inline editing.
Fixing issue with javadoc generation using java 7.
Improved validation result display.
Updated GWT dependencies to version 2.6.0 and added target compatibility
setting.
Merge commit 'd1512b640dc116b2b131df36f2b6cd20e425eb2d' into branch_3_x

Conflicts:
	gradle.properties
Adjusted fullscreen styling for current tinyMCE version.
Fixing issue where warning messages where not always displayed.
Fixing issue where child handler lists were not initialized properly.
Adding method to remove entity ids from the validation context.