Send notifications when extending volume

- Send resize.start when volume extension begins.
- Send resize.end with new size when volume extension ends.

Fixes: bug #1219106
Change-Id: I729da1604668080ec1a5d096df211aa55913dc48
Replace assertEquals with assertEqual - 1/2

The method assertEquals has been deprecated since python 2.7.
http://docs.python.org/2/library/unittest.html#deprecated-aliases

Also in Python 3, a deprecated warning is raised when using assertEquals
therefore we should use assertEqual instead.

This patch is a mere sed replace of one-liner assertEquals to assertEqual.

grep -lR "assertEquals(" cinder/tests/* | \
xargs sed -ri 's/(\W+self.assertEqual)s(.+)(\)$)/\1\2\3/'

Change-Id: I4feea94d53afa866af9b7e14bd80345fa7276e75
Do not attempt vg.update on uninitialized vg

It's possible for the scheduler to send the periodic
stats update request *before* the volume service/driver
has finished initializing, resulting in an exception trace
being logged.

This change adds a check to verify that the vg is actually
initialized (completed check_for_setup_error) and it also
removes all of the duplication of each LVM class driver.

To deal with other drivers that may have similar issues,
add initialized member to base driver, that member is
set False on __init__ and is updated by the manager
after running check_for_setup_error.  We also skip
update_stats if initialization isn't set True.

Rather than have a separate copy of update_stats in every
driver, we have one in the base LVM class and we set the two
unique variables as member parameters.

Fixes bug 1221874

Change-Id: I159e98a77782b8b2c85a8dd956b150828358fd25
Check cinder-backup service before "backing-up"

If cinder-backup service is not enabled, "cinder backup-create"
command fails like the following. As the result, the volume status
has been changed to "backing-up" in spite of not backing-up.

$ cinder backup-create f48aa6ae-4c35-4a6a-a393-5a5cf610945a
ERROR: Service cinder-backup could not be found.
$ cinder list
+--+------------+--------------+------+-------------+----------+-------------+
|ID|   Status   | Display Name | Size | Volume Type | Bootable | Attached to |
+--+------------+--------------+------+-------------+----------+-------------+
|..| backing-up |   vol-test   |  1   |     None    |  False   |             |
+--+------------+--------------+------+-------------+----------+-------------+
$

To avoid this situation, this patch moves the cinder-backup check
before changing a volume status to "backing-up".

Fixes bug #1221012

Change-Id: I42ad41e1cfb6fdb7feebe39a9a5f0356a41d7838
Merge "Replace assertEquals with assertEqual - 1/2"
Merge "Do not attempt vg.update on uninitialized vg"
Merge "Check cinder-backup service before "backing-up""
Merge "Send notifications when extending volume"