add WebP support
fix some issues
fix for mac
fix for win32
update libwebp to 2.1
add support RGB888, RGB565,RGBA4444
fix some issues
remove RGB565 support
Merge branch 'upstream_master' into add_webp_support
merge upstream
fix for android
remove duplicate codes
Merge branch 'add_webp_support' of https://github.com/dualface/cocos2d-x into iss1770-webp

Conflicts:
	scripting/javascript/bindings/generated
issue #1770: Adding test_image.webp.
issue #1770: Updating iOS project configuration and adding WEBP test demo.
issue #1770: Webp works ok on Android and iOS.
issue #1770: Adding webp support for blackberry and marmalade.
issue #1770: Adding webp support for win32.
issue #1770: Adding webp support for mac port.
Merge branch 'iss1770-webp' of https://github.com/dumganhar/cocos2d-x into iss1770-webp
issue #1770: Adding webp image format support for linux 64bit.