Add Hyper-V driver in the "compute_driver" option description

The description of the option "compute_driver" should include
hyperv.HyperVDriver along with the other supported driver.

Conflicts:
        nova/virt/driver.py
        nova/virt/hyperv/__init__.py

Closes-bug: #1347777
(cherry picked from commit b856bc5e348cc69923e3ee815303804323730026)

Change-Id: Ic7e16fd5154609987b2ef0b6f8ee52619ccf489c
db: Add @_retry_on_deadlock to service_update()

Add the _retry_on_deadlock decorator to the service_update() method of
nova's sqlalchemy API.  This decorator is scattered throughout the
sqlalchemy API for other methods that may encounter this error.  The
referenced bug report shows a trace from where it occurred on this
method.

Change-Id: I93b370d6457d2e85493be01a62a76404d228a6fa
Closes-bug: #1370191
(cherry picked from commit 61d54f2652424279af81c4084e87651044fac4bd)
Merge "Add Hyper-V driver in the "compute_driver" option description" into stable/havana
Merge "db: Add @_retry_on_deadlock to service_update()" into stable/havana