help: show advanced, experimental and deprecated extensions with --verbose I noticed that phabricator and absorb weren't showing up, no matter what. There's a related problem where commands for these extensions *do* show up without --verbose. I'm not sure what the point of hiding the extensions, but not the commands is.

help: remove a duplicate category name entry for TOPIC_CATEGORY_NONE

phabricator: assign commands to help categories `phabsend` and `phabupdate` seem pretty close to `email`. `phabread` is a little less close, but can be trivially used to actually import patches.