Add coffescript syntax highlighting

Imported lexer from Scintilla and added coffeescript filetype
For example yeah.

FTR, for C and C++ that also have this "globalclass" list, we use it to highlight custom types from tags (tags files and session tags) (to do so, set the 3rd column in highlightingmappings to TRUE).  It's not very relevant here as there's no tag parser for coffee (yet?), and I'm not even sure it's really relevant for CoffeeScript as a whole as IIUC it doesn't really have types as C or C++ can have, only classes.