The -tt means modules that mix tabs and spaces will be rejected.
The -E refuses to believe Python options in the environment.

reachable from Lib/.

between passes:  Win9x DOS boxes are limited to 50 lines max, and the result
of the first pass scrolls off irretrievably otherwise.  Also simplified
the goto-laden logic a bit.

New option "-q" to leave .pyc/.pyo alone.

tests for the first time -- like the Unix Makefile does.  This
avoids not catching problems in the bytecode generator and/or bytecode
marshalling.

directory less tedious.