UI Coverage pytest plugin!

Collateral damage:
- Minor changes to centralize creation of the cfme commandline option group
- SSHClient put_file and get_file accept kwargs, so now they can be recursive
Wait for appliance UI to come up after restarting

A little hacky due to the __init__.py in scripts/, but this should
all be made better as the Appliance class improves and moves that
functionality back into utils where it belonds.