Template re-sync and various other features and fixes

[blag]

I'll rebase this off of #98 once everything is up and working.

This PR corrects some of the "development drift" that has happened from people modifying Dockerfiles directly instead of modifying the Dockerfile templates and running update.py, and changes the Dockerfile templates to generate the content of the various Dockerfiles.

I have some very small improvements to the update.py script locally that I'm trying to wrap up, as well as adding a Makefile with targets to:

• automagically create a virtualenv
• install requirements
• run update.py
• check that the Dockerfile templates and the Dockerfiles were all updated together

And I'd like to integrate that into a CI test for this repo to ensure that the Dockerfile templates and the Dockerfiles themselves are always in sync.

[blag]

I'll make a new PR removing the templates. Do we still need the dist.yml and suite.yml files then?

[arm4b]

Nah, those files are garbage as well.