Fix subnet residue when resource deletion

Should set resource_id immediately after creating subnet
successful, otherwise the subnet resource will residue
when deletion.

Change-Id: I7974272d6a4b394775d971e2636bd1d4d5b78562
Closes-bug: #1370973
Skip validation if depends on not created resource

Using references on resources defined in template may be cause
of error during validation. This fix checks reference on another
resource and skips validation if resource is in INIT state.

Change-Id: I95531a1603de1e8c4b9f0f4b05b62eebc48beb3c
Co-Authored-By: Zane Bitter <zbitter@redhat.com>
Closes-Bug: #1347571
Closes-Bug: #1339942
Remove unused network_utils

This module is not used anymore.

Change-Id: I5205ec64c107cf59d04ca4dfbf3fe7367d5f8378
Merge "Fix subnet residue when resource deletion"
Merge "Skip validation if depends on not created resource"
Merge "Remove unused network_utils"