fixed draw count display

It was wrong when there were only quads on the stage (no images).
added 'alignPivot' method to DisplayObject class (closes #293)
added optional 'id' paramter to 'TouchEvent.getTouch' method (closes #198)
now removing text field from Button if text is empty
now logging warning when adding the same asset name twice (closes #339)

Previously, an exception was thrown.
added support for RectangleTextures in AIR 3.8
now broadcasting keyboard events to all display objects
added support for updated ATF file format
Fix textBounds for empty TextFields

Currently, empty TextFields with composed contents report nonsense
bounds. This commit initializes an empty TextField's bounds to
0, 0, 0, 0.
Merge branch 'emptyTextFieldBoundsFix' into develop