Added watching option to sel_container
Merge pull request #1042 from psav/sel_container

Added watching option to sel_container
_test_vm_power() finished

1. Fixed problems with _test_vm_power().
2. Modified test_permissions to print the traceback of any errors that arise during permission tests, instead of just the error,
3. Added get_number_of_vms() and get_first_vm() to cfme/infrastructure/virtual_machines.py
4. refactored the quadicon locator for cfme/infrastructure/virtual_machines.py into a module-level constant for better reuse.
flake8 fixes
added test for vm provisioning permission
Added test_permission_edit(), which ensures that changes to permissions are observed on next login.