Remove --debug-and-release support from mojob.sh.

(The fewer features it has, the easier it'll be to rewrite in Python.)

Also rename --use-goma/--no-use-goma to --goma/--no-goma.

Also, undo what I did for the default settings. (Oops, I landed the
wrong change previously.)

R=jamesr@chromium.org

Review URL: https://codereview.chromium.org/660343005