automatic handling of unconventional glyphs

[drammock]

would be good to have a function for auto-cleaning some of the common glyph synonyms (stuff that won't get caught automatically by denormalization) such as:

• two-story vs one-story [g]
• precomposed digraphs for affricates
• colons vs real length markers
• c-cedilla
• apical vowel symbols commonly used by sinologists
• precomposed rhotic-wing characters
• breathy stops ʱ vs combining diaresis below
• vowel-glide combos (like aj and aʲ) should become aɪ or ai̯
• others?

this could get built into the orderIPA function or could be its own function.

cc: phoible/phoible.github.io#9 phoible/phoible.github.io#10