Default to linuxbridge and openvswitch drivers for ML2.

Since the addition of ML2 port-binding, the linuxbridge and openvswitch
drivers are required to be loaded when running with ML2. This small
patch adds their loading into ML2 into devstack.

Fixes bug 1220743

Change-Id: I97c5f4e0e4af59766e0084ed3b2dea2843cb33bf
Modify midonet plugin to support the latest MidoNet

MidoNet has been upgraded and devstack needs to be updated to
be compatible.  This change is required to run the current
version of MidoNet plugin with DevStack.

Closes-Bug: #1222314
Change-Id: If3379b4d5da4e4fcf989ee7398b5952d71b68d5a
Augment instead of override extra ML2 options.

The existing ML2 code overwrote extra options set in localrc with
defualt values in some cases. This fixes it so it no longer does
that and instead adds to rather than overrides those values.

Fixes bug 1222854

Change-Id: Iafdaad7d4253f1b61e8a214c50adaf7599a641f2
Lower Heat max_template_size for Tempest

The default size leaves a very large padding for users to create larger
templates, but for testing and development a 10kB template is plenty.

This value is specifically meant to mirror upcoming changes to tempest
so that they are unified and can be tested in lock-step.

Change-Id: I0ea9798018a6d864ac04429c3ac89fb374583fb6
Swift: configure Ceilometer when it is enabled

This allows the storage.objects.{incoming,outgoing}.bytes measurements to be
easily used.

Closes-Bug: #1221097
Change-Id: If988a85930d7df1e043997763c3b5ebd720d6d86
Configure VPNaaS Horizon panel if q-vpn is enabled

Change-Id: I062fd31cb1de50f356c2c549a783d9c597b129fa
Closes-Bug: #1223012
enable volume backup tests if c-bak is enabled

this will set to True the tempest volume/volume_backup_enabled
option if c-bak is in ENABLED_SERVICES

Change-Id: I69931d668411fc8144d0fdb2f58ad9b6e987f793
Merge "Swift: configure Ceilometer when it is enabled"
Merge "Default to linuxbridge and openvswitch drivers for ML2."
Merge "Augment instead of override extra ML2 options."
Merge "Modify midonet plugin to support the latest MidoNet"
Merge "Configure VPNaaS Horizon panel if q-vpn is enabled"
Merge "enable volume backup tests if c-bak is enabled"
Merge "Lower Heat max_template_size for Tempest"
Merge branch 'master' of github.com:openstack-dev/devstack