Documentation for the Clojure feature

Fix Clojure packaging to comply with our guidelines

This is almost complete -- will land the changes once Kushal and myself can verify that the change works on RHEL 6 as well

Package Leiningen dependencies

Package Leiningen

Ensure Leiningen is configured to use the system Maven repository

Ensure that the default Leiningen project templates refer to the packaged versions of Clojure libraries

Package Clojure frameworks

Create a packaging guideline for Clojure packages