Filter network by project id

Need filter the networks by project id when show the networks with
normal user

Fix bug 1186867

Change-Id: I10b5880070a569614f54fa7dbcf08e548bcbc924
(cherry picked from commit 2a7f08ae4abca51dc60a02deee06a108ad1c4dcc)
Assert backing_file should exist before attempting to create it

Fixes bug 1200249

Change-Id: If7878361711f835247aaf64ce26f0058f8c4b5ba
(cherry picked from commit 879565efe51f19bd6f4d69d1b430b995f62106c8)
Merge "Filter network by project id" into stable/grizzly
Merge "Assert backing_file should exist before attempting to create it" into stable/grizzly
Merge remote-tracking branch 'upstream/stable/grizzly' into stable/grizzly