Revert "Devstack support for Neutron VPNaaS"

This reverts commit 8450a92a4d0299fff89717e665ce31d54731d3f0.

Change-Id: I6dd0f44a1a57735de292bc4ed4eaa929dc308297
Merge "Revert "Devstack support for Neutron VPNaaS""
Merge commit 'refs/changes/83/86083/1' of git://gold.eng.hq.xensource.com/git/github/openstack-dev/devstack into tmpbranch