Merge pull request #6990 from Dhilan007/v3-wp8fix

fixed WP8 project:compile error,missing files,wrong file path.
refactor UIButton setColor & setOpacity
refactor UICheckBox setColor & setOpacity
refactor ImageView setColor & setOpacity
refactor LoadingBar setColor & setOpacity
refactor Slider setColor & setOpacity
refactor Text setColor & setOpacity
refactor TextAtlas setColor & setOpacity
refactor TextBMFont setColor & setOpacity
refactor TextField setColor & setOpacity
refactor Widget setColor & setOpacity
refactor Scale9Sprite setColor & setOpacity
Merge pull request #6991 from andyque/fixUIFrameColorAndOpacity

fix UI frame cascade color and opacity