Retry lvremove with ignore_suspended_devices

A lvremove -f might leave behind suspended devices
when it is racing with udev or other processes
still accessing any of the device files. The previous
solution of using lvchange -an on the LV had the
side-effect of deactivating origin LVs alongway in
the thick volume case, which was undesired.

It turns out retrying the deactivation twice and
ignoring the suspended devices on the second iteration
avoids the hang of all LVM operations after an initial
failure.

Change-Id: I0d6fb74084d049ea184e68f2dcc4e74f400b7dbd
Closes-Bug: #1317075
Related-Bug: #1270192
(cherry picked from commit da9597aed0186e68dbf1c7304b30e49f8e6a54ff)
Get updated model info on volume transfer

On some drivers CHAP credentials are tied to accounts
which may be unique for each OS and/or backend Tenant.

For example:
  Volume is created with project_id xyz
  Backend creates an account for xyz with specific CHAP

  Volume is transferred to project_id abc

Currently we don't update the model_info, so even though
on the backend we updated the owner and CHAP settings we
never propogated that back up to the DB object so the volume
can't be used by the new owner.

This patch just adds an option to return model_update
on the accept_transfer call to the driver and updates
the db accordingly.

Also adds a call in the SF driver to actually get the
new model info to be fed back to the manager.

Closes-Bug: #1349475

Conflicts:
	cinder/volume/drivers/solidfire.py

Change-Id: Ie0447cdad69c4fbee99b4b6b1d3cacdfdd14137d
Set python hash seed to 0 in tox.ini

New tox (>=1.7.0) sets a random python hash seed by default. This is
generally good for testing because it will help keep projects working
regardless of the hash seed, but cinder unittests don't currently pass
with a random hash seed so set it to the python default seed.

This change will allow us to use new tox again and remove the
restriction on tox<=1.6.1 to run unittests.

Redundant setenvs for specific test envs are removed to prevent them
from overriding the PYTHONHASHSEED value.

Note this change will need to be backported to the stable branches to
keep unittests there working with new tox as well.

Change-Id: Ia55031528d082a1b11da6890447c5584e9e27551
(cherry picked from commit 03293715b1e950cf406018058e4c8a514c0f977f)
Merge "Set python hash seed to 0 in tox.ini" into stable/icehouse
Merge "Retry lvremove with ignore_suspended_devices" into stable/icehouse