PDF backend

able to do font subsetting. I was going to look into the

    > Fonttools library by Just van Rossum, but lately I've been
    > too busy with other things to.

FYI, matplotlib used to depend on fonttools, but we found the
dependency too onerous and booted it and wrote our own, lighter
freetype support. So I would be reluctant to reintroduce this
dependency.

JDH