Give a general purpose rake command for running django-admin in the right way for either the lms or the cms

Exclude things during .deb packaging correctly, so that we don't have a bunch of build detritus left over. FPM still leaves the empty directories, unfortunately

Don't pipeline in dev environment, which means that there is no need to run collectstatic either. Hooray\!

Delete settings.py in favor of envs/*.py, and add a rake task to run a dev server locally from those settings

Revert "Use git to get the branch name and commit number, rather than incoming environment variables"

This reverts commit d6a57558.