Allow user files to be in whatever lange they like

Out of the box, coffee-script will have been registered, but if they 
want to use clojurescript config files or cson, all they have to do is
register it at the top of their Brocfiles. Wee!

resolves #28
fix other references
require path typo
Merge pull request #35 from cabbagejs/coffee-config

Coffee config
whoops accidentally stopped deleting added files!
Initial go of environmental configuration instead of env checks.
Wrapping the pipeline related config into an object on config, so js & css aren't at the root.