Docs: Revise music21 installation instructions

music21 used to require special flags to allow installation with pip. This isn't
the case any more, so I've removed the flags from the Deployment Guide.
Docs: Remove Publican-based Deployment Guide in favour of rST Version

I like Publican, but virtually nobody else uses it, and it's even a bit of a
hassle for me... but all the Python developers love reStructured Text!
Docs: some old revisions to the Deployment Guide
Refactor: views.py/run_experiment() calls WorkflowManager.output()

Previously, run_experiment() would call the now-removed export() method.
Now it calls output() all the time.