updated versions in DependencyBank
[maven-release-plugin] prepare release 1.3.1
[maven-release-plugin] prepare for next development iteration
updated CHANGES
increased Version
add getRegion to PolygonSprite
Javadoc

Closes #2236
Add ability to set a tile's texture region
Add frequencyHz and dampingRatio

Closes #2245
DebugDrawer improved.
Disposing.
Lazy initialization. Removed unnecessary fields.
NPE fix.
Merge pull request #2249 from nooone/debugdrawer

DebugDrawer improved.
Stage.act() calls requestRendering() if any actions are added or fired (fixes #2228)
Stage#setActionsRequestRendering will animate actions when setContinuousRendering is false.