Now parses metalanguage udiprops; The parser mode is determined by the
presence or absence of the "-meta" command line option.

* Grouped statements in the main parser function such that meta-only statements
  will cause an error in driver mode, and vice versa.
* Added lists for provisions and ranks.
* Added parseProvides.
* Main driver-header struct now also takes a category index.
* Main driver-header struct now also takes a rank-file offset.