[mdb-dev] catalog updates

[Carl S. <cgs...@wo...>]

suggested names:

in libmdb/catalog.c:
  in mdb_get_objtype_string change the "Unknown 08" to Relationship
  in mdb_get_objtype_string change the "Unknown 0b" to Database
Properties

in include/mdbtools.h
  change the enum MDB_UNKNOWN_08 to MDB_RELATIONSHIP
  change the enum MDB_UNKNOWN_0B to MDB_DATABASE_PROPERTY