Related-Bug: #1390392

1. Updated menu.xml such that relevant menus will be shown in case of vCenter & vCenter + OpenStack
2. Hide CPU/Memory for Instances in case of vCenter mode
3. Enable Monitor > Infrastructure,Configure > Infrastructure menu in case of only vcenter
   orchestration mode
4. Show only one subnet while creating network in case of vCenter

Change-Id: I9eaf640184dbb63469bc873c7a1d872c93375991
Related-Bug: #1390392

1. Added checks while waiting for new network to be synced-up in API
   Server.
2. Ensure that there no vmi back refs & instance ip back refs before
   deleting network

Change-Id: Ie254b81a4809df85c8ef8f23dee73d8c94588232
Related-Bug: #1390392

Filtering the VCenter projects,networks,instances fromt the API server and displaying in corresponding pages of network monitoring,in case if the orchestration model is VCenter.
Change-Id: I7c2a52f470f987852f1ecde912154d9d42ddd370
Merge pull request #46 from Juniper/master

Pull changes from Juniper/web-controller to absingla/web-controller