WIP lesscss integration. #112

don't comment on surrounding changes (config & autoloader). i just wanted this branch to be testable out of box
I think at this point you want to check all the supporting file mtimes; invalidate the cache if any of them have changed; and store a private lastModified value that would just be read by getLastModified(). So I think you actually need to store two things in the cache: 1. the lessc array, and 2. the old max(all the files).