various updates

(-_-)
add button to hide ime
Fix lint errors
major refactoring for public release
Add more comments for better understanding of the code.
Rename the project into qslide-example
fix: forget to call super.onPause(), onStop(), etc.
Add code to test onOverlayStateChanged()
Add drawing activity for testing fullScreen and overIme
Add skipGuidePopup and ignoreMaxFloating meta-data tag
add more items to ListActivity to test scroll behavior
add test code for registerReceiver/unregisterReceiver ...

... on DrawingActivity