Fixed atlas index
Index is always (gid-1), so the processing order of the tile sets does not matter.
Fixed rare crash on Keyboard.isKeyDown

Fixes #1090
Added getKeyFrames() function

Added getKeyFrames() method to get the array where the Animation's frames are stored.
Added FBO.end(x, y, width, height) method

Added parametrised FBO#end(...) method that restores the viewport sizes
passed as arguments.
Support for zero-width widgets. Described edge use cases in javadoc.
Simple helper method to check if actor handles input events.
Add default button that set the particle sprite to 'particle.png'
Use a constant for the default particle
Merge pull request #1100 from veger/particleeditor-1

Add default button that set the particle sprite to 'particle.png'
Merge pull request #1102 from greek1979/master

Minor changes in UI widgets
Add controller listeners clear method

I find this usefull
javadoc
Update default.fragment.glsl
Update DirectionalShadowLight.java
Only get the contact list once
TextField#getSelection fix
Merge pull request #1107 from seroperson/master

TextField#getSelection fix
[android] add AndroidApplicationConfiguration.disableAudio option
Merge pull request #1109 from batesj/useAudio

[android] add AndroidApplicationConfiguration.disableAudio option
Sync with change in core