issue #4861, refactor setFocused into setHilighted
issue #4861, add focus functionality into Widget class
issue #4861, add CCEventFocus and CCEventListener
issue #4861. add android keypad support
issue #4861. cleanup some code of UILayout and UIWidget
issue #4861. add a horizontal focus test
issue #4861. fix android compile error
issue #4861, improve the horizontal layout test
issue #4861. refactor UILayout to search widget by index
issue #4861, fix widget query method
issue #4861, fixed a widget bug and add VBox test
issue #4861, Merge branch 'v3' into focus3861

Conflicts:
	build/cocos2d_tests.xcodeproj/project.pbxproj
issue #3861. add license to CCEventFocus and CCEventListenerFocus
issue #3861. fix a indent problem
issue #3861, fix linux compile error
issue #3861, fixs windows compile error
issue #3861, fix layout contentSize caculation
closed #3861, fixed some typo and indent problem
issue #4861, improve UIFocusTest, add click event to ImageView
issue #4861, refactor UIFocusTest, simplify code