* Wrapped brd's "main" section in an if __name__ == '__main__' block so that it can be loaded as a module.
* Fixed path sourcing issue for brd in brd_unit_base.
* TestMisc, as it is so far, is working.
* Fleshed out "table data" data structure
* Verified that calc_fingerprint(), populate_db_table(), populate_db_from_tree(), and build_tree() all work.
* Added a general directory schema.
* test_new_fingerprint() and test_update_fingerprint in TestCheckDB are both working now.
* test_create_db() in TestMisc has been finished.