These have keybindings of '+', '-', and 'a'. The bug they have so
far is lack of visual feedback for their effect, and lack of undo.
(Also the fact that adding or removing a single tag for a thread
takes way too long--but that's as a Xapian issue as discussed here:
replace_document should make minimal changes to database file
http://trac.xapian.org/ticket/250
)
We now get the point staying right at the top where we want it.
We also don't get any extraneous noise about "Process notmuch
completed" or anything like that. Just the output in a read-only
buffer.
Compilation mode does a bunch of things that we don't want. Instead
of trying to tear it down to what we want, let's start at the other
end and build up only things that we really want.
I'm using that file as my reference here, so I'm likely to end up
copying some code here or there. Might as well be safe and just
copy the copyright statement.