modify tests, and add vm class
ignore bak files
Merge branch 'master' of github.com:ZHAndyWu/Eisenbahn into vmhost
change vm_host url to api/host/hardware
add api/host/vms implementation
modified some unit tests
and fixed bugs
vm actions
snapshot actions, guest os operation
Merge branch 'vmhost', remote-tracking branch 'origin'
Merge branch 'master' of github.com:ZHAndyWu/Eisenbahn

Conflicts:
	Eisenbahndamm/tests/test_vm_host.py
	Eisenbahndamm/vm_tools.py
	Eisenbahndamm/warehouse/db_utils.py
	Eisenbahndamm/warehouse/depository.py
	Eisenbahndamm/warehouse/models.py
	Shared/sync_utils.py
scheduler