Revert "UFO3 guidelines"
Revert "UFO3 guidelines"

This reverts commits 494a63190082d80a587386e99f5a89e91a67b59c and
a301c76a8c6324120de398c07c2d1f9d3e858696.

UFO3 guideline support in Defcon and MutatorMath is unstable, so these
need to be reverted for now.

googlei18n/glyphsLib,googlefonts/glyphsLib