Support Emoji

+ Changed the range of double wide characters for Emoji. From U+1F000 to U+1FFFD. Ref. http://en.wikipedia.org/wiki/Emoji
+ Using 'Apple Color Emoji' font for rendering emoji with NSFontDescriptor -fontDescriptorByAddingAttributes:
+ Fixed rendering for Surrogate pair chars, CTFontGetGlyphsForCharacters returns 0 for Surrogate high char glyphs
update app and document icon for Yosemite
tweaks to shadows
[change] Add more contrast to the active tab
Merge branch 'yosemite-icon' of https://github.com/jasonlong/macvim
[add] icons for yosemite
Merge branch 'macvim/feat/emoji' of https://github.com/splhack/macvim
[add] Emoji support
Merge branch 'master' of https://github.com/dokenzy/macvim