Refactor bisect.pl to use Getopt::Long's pass_through option.

Refactor bisect.pl to use Getopt::Long's pass_through option.

Add a --check-args option to bisect-runner.pl to validate the arguments that
bisect.pl doesn't know how to check (else the automatic start detection
will get very confused by invalid arguments). Switch bisect.pl to bundling,
which permits the "traditional" make argument form of -j4 to be used instead
of -j=4. As this actually makes -j=4 invalid syntax now (an error about the
unknown option "="), change the syntax messages.