Add string 'quantum'/ version to scope/tag in NVP

This patch adds scope='quantum', tag=QUANTUM_VERSION to each element
created in NVP via quantum. This patch also removes the function
set_tenant_id_tag() as it was only used in one place and wasn't very useful.

Fixes bug 1128674

Change-Id: I9f1f8e9b49154012a82d24e31cc9fb7f2df9c604
Metadata agent: reuse authentication info across eventlet threads

Fixes bug 1152429

Change-Id: Ib65f08a46feb14abc97c0c83e57d076abd372a2c
Merge "Add string 'quantum'/ version to scope/tag in NVP"
Merge "Metadata agent: reuse authentication info across eventlet threads"