Revert "Let the entry point handle the sys.exit"

This reverts commit 04d30023fc493ad16a583fd821171c478fb0d76b.
Revert "route around the entry point"

This reverts commit 221837c977cb02fd2aaa91f99433532e11820cfd.
Revert "Explicitly flush sys.stdout and sys.stderr before sys.exit()"

This reverts commit dc1e3811896babc3bf9e024c1ee59c17cbfdd92d.
Really?