Avoid RequestURITooLong exception in metadata agent

Length of API port query is proportional to number of networks
and may exceed URI limit. The solution is to query ports by
given ip address only and then filter them by network_id.

Closes bug 1348097

Change-Id: I2a87d6b215df380b24dd5ebb24947e8729f3f6fb
Add definition for new VIF type

The type VIF_TYPE_DVS is added. This indicates that the port
will be added to a VMware distributed virtual switch.

This is for blueprint vsphere-neutron.

Change-Id: I1b5df837734af9a3f7d48b60de120592b11e392e
Merge "Add definition for new VIF type"
Merge "Avoid RequestURITooLong exception in metadata agent"