Maps get a shrink method.

Rejoice.
Don't need these methods.
Allow null outputDir string.
Merge branch 'origin/master'
Added a random boolean with chance
Merge pull request #537 from xXMarkuski/mathUtils

Added a random boolean with chance
Updated randomBoolean with chance.
Expose textEquals.
Maps get a clear(int), more efficient than clear then shrink.

I love having so many maps. Could use a few moar.
Add DepthTestAttribute to GWT module def
Fix SkinLoader dependency logic

Fixes Issue 1625.
setDisabled for Slider.
Merge branch 'origin/master'
Change MusicLoader and SoundLoader to async
Remove rogue import
Fixed disabled.
Added premultiplyAlpha.
Merge branch 'origin/master'
Merge branch 'master' of https://github.com/libgdx/libgdx