Fix digit/keycap unicode code points

Emoji digits and # are normal ASCII digits followed by COMBINING ENCLOSING KEYCAP (0x20e3). http://www.unicode.org/~scherer/emoji4unicode/20091221/emojidata.html
Added methods to convert emojis to and from unicode characters
Added an example for  in the README
Removed an unnecessary check in the README reverse_emojify example
Fixed the unicode encoding
Alias :dolphin: -> :flipper:

Is this how this works?
Ah -- do the :flipper: symlink thing
Update LICENSE for the source code
Merge remote-tracking branch 'mbillard/master'