Update to PLUMgrid plugin configuration

Fix bug #1206308
Add function for security groups
Add function for ovs check
Update plugin class configuration

Change-Id: I603e902f985277a61f162abdfffd6430cc00efaa
Install things in setup_develop with pip -e

We have some complex logic in here to try to do the right things with
the requirements before doing the install of the package which still
winds up being wrong in some cases. Since having written this code,
we've learned that the logic we're trying to achieve is actually what
pip install -e does. So just use that. We have to follow up with a chown
of the resulting egg-info directory, because the sudo command will cause
it to be written by root, which prevents subsequent commands from
operating without privilege in the directory.
Change-Id: Iffd068c94ef84475ebb30758bcf612075d225bea
Remove installation of python-netaddr

System and pip installation of this conflit and cause breakages.

Change-Id: I87a03f88a134683310d6ec0bd62d86c5007fcd72
Merge "Update to PLUMgrid plugin configuration"
Merge branch 'master' of git://github.com/openstack-dev/devstack into opendaylight
Correct the location of the OVSDB git repository. devstack now correctly
loads OVSDB into ODL.