[PATCH v2 1/2] emacs: tree: remove binding for pressing button in message pane

[David Bremner]

Mark Walters <markwalters1009 at gmail.com> writes:

> We want to use "e" for editting postponed messages in show, and in
> tree view, so remove the binding for the function which does
>

This needs rebasing. I did the merge by hand and I think it works out,
but other recent changes to notmuch-tree.el conflict. Also editing is
mispeled.