Support building a packaged jar with leiningen.
Workaround to very slow compile caused by gen-class in main:
we have  a dynamic main that looks up our real main and calls it,
hidden so gen-class applies only to that and not recursively.
Update procfile to reflect that we now set main in project.clj
Merge pull request #1 from paul-lshift/uberjar

Support uberjar building