Replace update.sh functionality

Currently we internally use a couple shell scripts to parse arguments and make sure a copy of ```ceph-qa-suite``` are checkout out before we run ```teuthology-suite```. That always seemed brittle and, more importantly, not fair to the community since those tools were kept out-of-tree. This PR adds the same functionality to teuthology itself.
this is extremely brittle. You are now (not sure if this was the case before) fully enforcing the need for an internet 
connection, working dns, *and* a working remote github service.

The tests should be abstracted so that they can work without connecting to github.