Enhanced job running.

Configure SLURM and make it the default job runner. Setup Docker to allow the container to do docker-in-docker as documented by Andrew Stewart https://github.com/andrewcstewart/galaxy-docker (but disable by default).
Merge branch 'jobs' of https://github.com/jmchilton/docker-galaxy-stable into jmchilton-jobs

Conflicts:
	galaxy/Dockerfile
	galaxy/startup.sh
add SLURM installation and configuration
Merge branch 'master' of https://github.com/bgruening/docker-galaxy-stable

Conflicts:
	galaxy/Dockerfile