Fix Neutron plugin XTRACE handling

The various Neutron plugin files need to have unique variables for the
xtrace state as they are sometimes nested more than two levels deep
and MY_XTRACE is getting stomped.  This gives each of the neutron_plugin
and neutron_thirdparty include files a unique XTRACE state variable.

I don't think this is a problem with any of the other plugin include
files (yet) so this just handles Neutron for now.

Change-Id: I7c272a48e7974edecaff5f431ff7443dd6622588
don't use pip -e install for libraries

libraries in openstack shouldn't be installed editable, as it
causes all manner of issues (especially complicated by the use
of namespace packages). Install these globally as part of the
devstack installation process.

Change-Id: I11acb169e74069be0618e57496ff342f9e788493
Trove: Set appropriate service URLs

Without setting these, they default to localhost which
works in the the gate, but may not work in all devstack
setups.

Change-Id: I50eadbf0b4975cf04ec945bcf463c2738e6e7a3c