Makeify the website build. (issue 5244045)

[percival . music . ca]

LGTM, thanks so much for cleaning this up!


http://codereview.appspot.com/5244045/diff/1/make/website.make
File make/website.make (right):

http://codereview.appspot.com/5244045/diff/1/make/website.make#newcode73
make/website.make:73: CREATE_VERSION=python
$(script-dir)/create-version-itexi.py
whoops, we're inconsistent in whether we use python or $(PYTHON).  Let's
leave it there for now, but it's something for future consideration

http://codereview.appspot.com/5244045/diff/1/make/website.make#newcode106
make/website.make:106: bib-files = $(OUT)/others-did.itexi
$(OUT)/we-wrote.itexi
we'll be able to remove the bib stuff once the dev/website-build
material has been added.  I'll have to re-do that stuff, but it'll be
easy with the new website.make.

http://codereview.appspot.com/5244045/