[PATCH] cli: some keyword options can be supplied with no argument

[David Bremner]

David Bremner <david at tethera.net> writes:

> From: Daniel Kahn Gillmor <dkg at fifthhorseman.net>
>
> We might change some notmuch command line tools that used to be
> booleans into keyword arguments.

pushed my #1 and the original #2 and #3 to release