Use teuthology.config.

Also use os.path.join()
Add doc noting Inktank's lockserver URL

Since I just removed it from lockstatus.py.
Use config.lock_server
Add config.ceph_git_base_url
Add a basic test for teuthology.config
Don't hardcode teuthology's git repo URL
Don't hardcode ceph.com mirror for linux-firmware
Don't hardcode the git://ceph.com/git/ mirror

Default to https://github.com/ceph/ but add a ~/teuthology.yaml option
Split test into two
Merge pull request #106 from ceph/wip-mirror

Remove lots of ceph.com hardcoding; default to upstream sources