As Spencer pointed out, using -DPDB_DIR is better than requiring an
explicit PDB dir everywhere. Also made Census and its subclasses print
usage messages.
Moving the census2.representatives package from protodomain-search to
symmetry. Also made significant improvements to
SuperfamilyRepresentatives: it now handles Sun Ids corresponding to
domains, species, and families.
Deprecated original symm.census.
Use ScopFactory methods instead.
Commented out extremely time-consuming tests.