Add coffescript syntax highlighting

Imported lexer from Scintilla and added coffeescript filetype
Hum, actually JavaSciprt filetype has it duplicated in `secondary`, as it already has it in `primary`.
And I didn't know one could use `prototype` as an identifier, I thought it was really special in Javascript, but apparently it's just a magic name, not a reserved one.  So, nevermind this remark.

However, we prefer to keep keywords sorted alphabetically for them to be easier to modify without introducing redundancy.