Freetype/font_config as font backend

[theRealProHacker]

We should use font_config to select which fonts to use for rendering. There are Python bindings available.

[theRealProHacker]

The existing text stack that we can (and should) use is:

• freetype (https://freetype.org/developer.html, https://github.com/nmcveity/pyfreetype, https://github.com/ldo/python_freetype)
• fontconfig (https://www.freedesktop.org/wiki/Software/fontconfig/, https://www.freedesktop.org/software/fontconfig/fontconfig-user.html, https://github.com/ldo/python_fontconfig)
• fribidi (fribidi.org, https://github.com/ldo/pybidi)
• harfbuzz (https://github.com/harfbuzz/harfbuzz, https://github.com/HinTak/harfbuzz-python-demos/blob/master/hb-view.py)
• pango (https://de.wikipedia.org/wiki/Pango)