Install mechanism packages for ml2 on RedHat

When using linuxbridge and/or openvswitch as ml2 mechanism_drivers,
install the necessary linuxbridge/openvswitch plugin package(s).

Change-Id: Id5bb4ab96701e0da15c82557f07ed304db76e65a
Closes-Bug: #1269672
metadata-agent: multi-worker support

Neutron Metadata Agent is now able to spawn multiple workers to improve
performances from hundreds or thousands of metadata-namespace-proxy processes.

This change addes a new "metadata_workers = XX" to the ini file
to support creating more workers to help improve performance.

Commit in Icehouse: http://git.io/Al4Xpw

Change-Id: I536dd6a758ec5dbc95a39b485130f8f16a235629
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
Don't be too strict for vlan_ranges

VLAN range can be also in format of physical network or with only
single ID. This patch makes those values pass the validation

For more info please check https://bugzilla.redhat.com/show_bug.cgi?id=1066549

Change-Id: I054fbd45ac2228a3a579c08cdd617d970abcaddf
Merge "Install mechanism packages for ml2 on RedHat"
Merge "metadata-agent: multi-worker support"
Merge "Don't be too strict for vlan_ranges"