Address U. F. O. shortcomings.

This attempts to address a number of issues mentioned in #1653, specifically the dropping of version data, the changing of glif names, and the reversal of reference and anchor orders. It also enables layered U. F. O. output in certain limited contexts outside of the specification.

U. F. O. does not support encodings, so we don't try to force Unicode (which can change names). If we discover that somebody has created a tag for the encoding, we may be able to support that here.