- Add your test to rendercheck.h TEST_*
- Add command line option to main.c case 't'.
- Add command line option to main.c usage()
- Add your test loop to the bottom of begin_test().  Looping on ops and dests is
  highly recommended.
- Write your test in t_testname.c and add to Makefile.am, with prototype in
  rendercheck.h
- Add a note about your test to README
- Be sure to include your MIT license boilerplate on the new file.
