make feature system descriptively adequate

[drammock]

adds some new features to make all attested pairs of contrasting phonemes actually have contrasting feature vectors. So far this means adding:

• lax (to handle downtack on close-mid vowels)
• aspirated (to handle devoiced breathy stop vs aspirated voiceless stop)
• apical and laminal:
  • considered a dependent feature of coronal (all +coronal sounds get a value for apical & laminal)
  • all retroflexes and taps/flaps are considered +apical by default
  • all alveolopalatals are considered +laminal by default
  • all other coronals are -apical,-laminal by default
  • 033A diacritic adds +apical,-laminal
  • 033B diacritic adds -apical,+laminal
  • NOTE: three diacritics are +coronal but do not set values for apical or laminal. they are the "rhoticization (wing)", the "linguolabial (seagull)", and the "dental (bridge)" diacritics

opening as draft, because so far this only eliminates 18 of the 51 non-contrasting pairs.