Bug 994986 - Remove 'rhc cartridge' because it conflicts with other aliases

Ruby 1.8.7 has random order hashes, and depending on how the commands load the 'rhc cartridge' alias (to list) and 'rhc cartridges' were getting confused.  Since we don't alias the root command in other scenarios, I've removed 'rhc cartridge' as an alias.
Merge pull request #441 from smarterclayton/bug_994986_remove_old_cartridge_alias

Merged by openshift-bot