Add clusterhq-release package.

This is a package containing the repository definition for our public repository.
Can you give an example or otherwise explain this?  I think it means the `Version` item in `clusterhq-release.spec` must match the `clusterhq-release-N-?.fc20.noarch.rpm` path being copied from (where `N` must match).  But `?` is a shell wildcard so I'm not entirely sure.