ACE code editor

Added ACE code editor to compile.html

TODO: ACE itself is BSD licensed - 
https://github.com/ajaxorg/ace/blob/master/LICENSE
So jor1k's LICENSE text file should reflect this (i.e. specify that the ACE sub-dir is BSD not GPL2)

All ACE's js files are in a subdir of js/lib/
Thanks to Neelabh for building the first working version.

FYI/TODO: The compile.html page could do with some better html-design to give it the same look and feel as index.html