Switch to Galaxy Standard Technology Stack

Pretty substantial change - sorry ahead of time and feel free to decline obviously.

For more information on deploying Galaxy using this stack see - https://wiki.galaxyproject.org/Events/GCC2014/TrainingDay/AdminWalkthrough.

Replaces Debian with Ubuntu 14.04 LTS - which is what CloudMan and devteam training materials target, and @natefoo builds packages for. This in turn requires updating to Postgres 9.3.

Replaces Apache with uWSGI + nginx (this has advantage of using multiple processes really easily and should be a little more performant). Likewise, instead of using OS services - this starts services with supervisor - this is manages all the services which simplifies startup.sh and provides and will restart processes that die for instance and simplifies startup.sh to some degree. (I think in the context of Docker especially supervisor makes more sense than OS services.)

I think there is value in usegalaxy.org running the same technology stack that CloudMan, Docker images, Ansible roles, and training materials use. It will hopefully simplify support, it is a stack that the devteam is confident can scale well, and hopefully these projects can evolve in tandem.