help: move 'additional help topics' code

help: rename option_lists to optlist

help: drop with_version If --version is specified, we print the version and exit (as documented).

dispatch: don't rewrap aliases that have the same definition Previously aliases that overrode existing commands would wrap the old alias on every call to dispatch() (twice actually), which is an obvious re-entrancy issue for things like the command server or TortoiseHG.