Oops, being a bit too strict on dependency qualifiers

Oops, being a bit too strict on dependency qualifiers
- Forgot how nasty hack parseBits() was... its abusing multilang
  support and the multilang support passes "C" if no lang is specified,
  which certainly isn't a valid qualifier. Make multilang vs tag with
  optional qualifiers different types in PreambleRec, which allows
  handling this more sanely
- Additionally build-dependencies dont take any qualifiers now