Fix 'start' cmdline arguments: bail on superfluous args.
For 'tickoff', change '--undo' to 'undo'; stricter args; tweak error messages.
Adjust 'tickoff' test script.
Allow 'now' as date argument to 'log'.
Add comment testscript.

Fix 'start' doc.
Fix 'recall' cmdline doc (rename from 'remember').
Add '-- <comment>' to 'adjust' cmdline doc (not implemented).