Include a file with hieroglyph metrics (currently unused)

We'll probably upgrade this with more coordinates at some point, for
actual drawing purposes.  But this is enough to get started with
the high-level layout algorithms.
Tweak metrics to give reasonable, rounded results
Convert mixed hieroglyphs/MdC to one or the other
Allow basic MdC to be used in hieroglyph rows

Right now we just flatten it out, but we'll eventually try to feed it all
to an MdC-compatible rendering library and make pretty images.
Document support for MdC characters in hieroglyph lines
Bump version to v0.0.2