[6/8] Settings: Theme engine

Change-Id: I9a0c9da454b5239a43d287af9f2df8c4d042d466

Conflicts:
	res/values/custom_strings.xml

Conflicts:
	res/drawable-hdpi/ic_settings_themes.png
	res/drawable-mdpi/ic_settings_themes.png
	res/drawable-xhdpi/ic_settings_themes.png
	res/values/bs_strings.xml
	res/xml/ose_screen_and_animations.xml