dev/website-build

[Graham Percival]

I'm working on simplications to the website build, mainly
involving a potential web-media repository on a separate branch
called dev/website-build.

Feel free to try it out and try to break it.  For a complete
build, you'll need my lilypond-extra git repository from github
https://github.com/gperciva/lilypond-extra
and you'll need a LILYPOND_WEB_MEDIA_GIT environment variable set
up (pointing at that repo), but if you don't have anything set up,
it should give you a decent error message.

Anybody should feel free to push to this branch directly with no
qualms or review.  When the dust settles, I'll propose formal
patches to master on a case-by-case basis, or something like that.

Cheers,
- Graham