added basic test support gem

I copied all of the support stuff from the global features
moved most of global features to use test gem

The only stuff that stayed is the stuff specific to the global features themselves.
moved media root stuff in env

Also cleaned up the way the media root was being handled
added configurable port for drivethrough
removed useless pathname require
moved helpers for gluegun features in test
gluegun features now use common bootstrap
gluegun features now use common rabbitmq
drivethrough rspec integration tests now use common test helpers
commons rspec integration tests now use common test helpers