Add copyright text to glance/openstack/common/__init__.py

Synchronize the content of glance/openstack/common/__init__.py to the
one in oslo-incubator.

Change-Id: Idd059e3f4d00d91c9a14cf302fd780044929e3e5
Closes-bug: #1288877
Makes possible to enable Registry API v1 and v2

This change will make possible to enable/disable both v1 and v2 Registry APIs
either individually or together from glance-registry.conf.

DocImpact
Closes bug: #1290432
Change-Id: Ib2458b3312bdb552975b1e42485086a1c3aa6d3f
Make the VMware datastore backend more robust

This patch contains several fixes related to invalid configurations
and corner cases:
- better error handling for the store operations
- better logging when response is not successful
- better support for various store_image_dir formats

Change-Id: I6c0003e29d621c1f71490cb9fce163dc840a113f
Closes-Bug: #1291646
Merge "Add copyright text to glance/openstack/common/__init__.py"