Add default voicing, streamline integrity checks
Add default voicing, streamline integrity checks

Add default voicing information to IPA letters that lacked it.
Use upper-case for type (feature) names, lower-case for (feature)
values. Simplify the integrity checks. Also check Unicode category.

googlei18n/language-resources,google/language-resources,google/language-resources,google/language-resources,googlei18n/language-resources,google/language-resources,google/language-resources,google/language-resources,googlei18n/language-resources,googlei18n/language-resources,googlei18n/language-resources,googlei18n/language-resources