* modifications to `configure.sh` so that it generates all
  the test scripts in the build directory
* more MacOS support in `configure.sh`; check to see if `.dSYM`
  folders are created when a test script is compiled, and, if so,
  don't forget to delete them when they're cleaned up.
* `makepage` now accepts markdown option flags a'la the `markdown`
  program  (via `-Fxxxx`, `-fname`, or in the `MARKDOWN_FLAGS`
  environment variable.)
* strip bitfields out of `opts[]` -- I can't initialize a bitfield
  on plan9 cc.
* add a `-E` flag to `theme` to disable context-sensitive `<?theme xxx?>`
  substitutions.