Modify kill and exit functions on emacs notmuch mode

[Tomi Ollila]

On Sat, Jun 03 2017, katsuyuki wrote:

> Hi, I modified kill and exit functions on emacs notmuch mode.
> I want to hear your opinion about the change.


Some years ago I had a problem notmuch choosing "strange" buffer when
exiting e.g. mail buffer (and I sent a patch to "fix" that). Eventually
the problem was in my own elisp configurations and after I fixed that
I've had no problems what buffer emacs choose when closing notmuch 
buffers. That doesn't mean that there could still be something to
improve there...

... but as someone(tm) may know, everyone have their own workflow
( https://xkcd.com/1172/ ) in their notmuch usage -- someone may
e.g. start writing email based on arbitrary C code buffer, and
after email send, return to that buffer instead of going to some
other notmuch buffer.

An alternative to this series would be adding a buffer selection
hook variable which anyone can set to bre^H^H^H^improve their
usage.

Tomi