* Added the basic structure to the Sweet parser in sch_part.cpp.
* Got inheritence working off of the 'extends' keyword and PART::inherit()
* Tossed the units support out of sweet.keywords, since we agreed to go dimensionless.
++richio:
* Added the problemInputLine support to PARSE_ERROR, so UI can show the
offending line of bytes. Yes bytes, not even guaranteed to be characters.