Use `TextSwitcher` to display Score.

Also do some refactors.
Update the merging algorithm.
Update the merging algorithm.

Remove all empty cells in a row/column by one swipe action.
Remove "()" from APP name.

Use `SharedPreferences.Editor.apply()` instead of `SharedPreferences.Editor.commit()` on Build.VERSION_CODES.GINGERBREAD+ devices.
Merge branch 'dev' of https://github.com/vhow/2048_mini into vhow-dev

Conflicts:
	app/src/com/gmail/dailyefforts/merge/MainActivity.java
Release v1.1