Cleanup tools/hacking using flake8

Change-Id: Ia151f265bf62e6704de6cc2f2c01963be9e2dd69
Move queue_get_for() from db to rpc.

Part of blueprint common-rpc.

The function queue_get_for() is a utility function used by various
consumers of the rpc API.  This function lived in the db API, but never
ended up using anything from the database.  This patch moves it into the
rpc API so that it can be used by other users of rpc once it moves into
openstack-common.

Change-Id: If92675beecff5471b416a929c161b810e3c71939
Add a note on why quota classes are unused in Nova

Quota classes can only be used if you write a custom middleware which
sets the quota_class context attribute. Nothing in OpenStack core does
this.

The only known middleware which does this is the rs_limits turnstile
preprocessor: https://github.com/klmitch/rs_limits

Add a note to the code to give others some chance of figuring this out
for themselves.

Change-Id: I52973f2f4d7f07f5121492e062dd31cadf02aa43
Update .gitignore

Add:
* ChangeLog
* nova/tests/coverage.xml

Change-Id: I1d0c395cf679e07e304dd878d97734307b685f4c
Merge "Move queue_get_for() from db to rpc."
Merge "Cleanup tools/hacking using flake8"
Merge "Update .gitignore"
Make sure an exception is logged when config file isn't found

Fixes bug 1006457

Since exception.ConfigNotFound was derived from exception.NotFound, it
would result in a silent 404 error being returned to the client instead
of logging a useful error message that a necessary config file was
missing and returning a 500 error.

Change-Id: I3abefae8d41be4013501ba1731fa49e3c93bde1a
Merge "Add a note on why quota classes are unused in Nova"
Prevent task_state changes during VERIFY_RESIZE.

Don't allow operations that cause task_state to change
when an instance is in VERIFY_RESIZE.

Fixes LP Bug #965630.

Change-Id: I7e222985c199d619c5cb248c04e1670c92d5587b
Remove unnecessary setting of XenAPI module attribute

This was moved to be class/instance attributes in a previous change
and the module attribute no longer needs to be set.

Change-Id: I413ba69444fdd2d246b060ef6280a547a3b46f76
Merge "Make sure an exception is logged when config file isn't found"
Merge "Prevent task_state changes during VERIFY_RESIZE."
Remove duplicate words in comments

Change-Id: I645692d66c6c007d5fbf40d4db16d7f36cbfd6fe
Merge "Remove unnecessary setting of XenAPI module attribute"
Remove list_disks/list_interfaces from virt driver

Removes the list_disks and list_interfaces functions from the
Nova virt driver. These functions are not used.

Fixes LP Bug #1007005.

Change-Id: I69296866f2cae712fbf7f0b8cb50c282714f04b8
Merge "Remove duplicate words in comments"
Merge "Remove list_disks/list_interfaces from virt driver"
Cleans up extraneous volume_api calls

 * Partially implements blueprint volume-decoupling
 * Deletes update() which should not be public
 * Removes extra call to update() in rollback live migration that
   was missed in an earlier patch
 * Deletes remove_from_compute() in preference to compute doing
   the call to the destination host directly
 * Removes wait_creation and moves the polling to the one place
   it is used

Change-Id: I63160e0fd048f82937a322bd068c3a9ff4f60336
Don't query nova-network on startup.

Fix bug 999698.

nova-compute requested network info for each instance on startup via rpc.
If all services get (re)started at the same time, nova-network may not
be available to take this request, resulting in a lost request.  To
combat this issue, get the network info from the cache in the database
on startup.  If by some chance this information is not correct, it will
get fixed up by a periodic task.

Change-Id: I0bbd475e078ac2a67c99c2be4711e86d617c609a