Switch to Oslo-Incubator's EnvFilter rootwrap

Nova-Network used to have its own class for DnsMasq rootwrap
filtering. This was generalized into a new EnvFilter rootwrap
filter that can specify both commands and environments to pass.

Update to openstack.common.rootwrap to git a117358 of
oslo-incubator's rootwrap. This includes the following commits
merged from oslo:

    3b16d31 Remove DnsmasqFilter and DeprecatedDnsmasqFilter
    f9d1a59 Handle empty arglists in Filters
    233baa2 Handle empty PATH environment variable
    3e74c00 Add IpFilter, IPNetnsExecFilter and EnvFilter
    8b95b1e Handle relative path arguments in Killfilter
    7119e29 Enable hacking H404 test.
    ea78eec Update KillFilter to stop at '\0' for readlink() function.

Related to: blueprint quantum-common-rootwrap

Change-Id: I125e5724259850dc4768fb236cbfa5df199008c0
Removed code for modular exponentiation, pow() already does this

Change-Id: If21cbcbeb60618769e1659a90381416dfc43ebc4
Remove clear_rabbit_queues script

The clear_rabbit_queues script has been around forever, but it doesn't
appear to be widely used - e.g. there is no user documentation for it
and I don't see any mentions of it on mailing lists or Q&A forums.

Also, RabbitMQ now includes a management plugin and CLI which allows
you do do e.g.

  $> rabbitmqadmin delete queue name=$topic
  $> rabbitmqadmin delete queue name=$topic.$host
  $> rabbitmqadmin delete exchange name=nova

oslo.messaging does not expose an API equivalent of this command since
even the existance of a queue is transport driver specific. We could
consider adding transport-specific admin CLIs, but probably not where
the transport already has suitable admin CLIs elsewhere.

For reference, this script was added by this merge:

  https://code.launchpad.net/~mdragon/nova/lp794635/+merge/71437

blueprint: oslo.messaging
Change-Id: If5e6354e8ace4c0b4425c96de558a5cbab4c98bd
Port "Accept is_public=None .." to v3 tree

The following commit(I2a9b1c24cd744c8819c1d41e0ad103d05398401c) have
not been merged to v3 tree now, because the commit was merged to the
existing api after porting flavors.py to v3 tree.

    commit 645c2d3a06bbf8b0854ebcc539ad33dd706866c5
    Author: Xavier Queralt <xqueralt@redhat.com>
    Date:   Wed Jun 12 14:59:29 2013 +0200

        Accept is_public=None when listing all flavors

This patch ports the commit to v3 tree.

Partially implements blueprint nova-v3-api

Change-Id: Id1ff1366c16f0caac50e279b2add5ec9d9b9bf5f
Moves compute.rpcapi.prep_resize call to conductor

This patch moves the prep_resize logic out of scheduler.manager
and creates it on conductor.manager.ComputeTaskManager.

Partially implements bp cold-migrations-to-conductor

Change-Id: I8458071fb13505f55f8d2155c9ec5ee938b1005f
Merge "Port "Accept is_public=None .." to v3 tree"
Merge "Remove clear_rabbit_queues script"
Merge "Removed code for modular exponentiation, pow() already does this"
Merge "Moves compute.rpcapi.prep_resize call to conductor"
Merge "Switch to Oslo-Incubator's EnvFilter rootwrap"