Remove unused pictures
Merge branch 'game' into gui
Implement back button at level screen
Hide title bar, status bar. New back button
New button level background
Merge branch 'game' of github.com:quannt24/zoo into gui

Conflicts:
	AndroidManifest.xml
	res/drawable-hdpi/animal.png
	res/drawable-hdpi/button_back.png
	res/drawable-hdpi/button_back_pressed.png
	res/drawable-hdpi/button_character_empty.png
	res/drawable-hdpi/button_level.png
	res/drawable-hdpi/button_level_pressed.png
Start game from level select screen
Merge branch 'gui' into game
merge game + gui

Signed-off-by: CaOSTe <lequana2@gmail.com>