darcs-notify: a light-weight replacement for darcs-monitor

Usage:

  darcs-notify setup [-f] Write a new _darcs/prefs/defaults to set up apply
                          posthooks (see below). Use option -f to overwrite
                          an existing defaults file (warning: this will
                          remove its prior content).

  darcs-notify post       Send email notification about new patches, using
                          .darcs-notify-template as a template. To be used
                          as apply posthook.

Prerequisits:

  * The current working directory should be the top of the darcs repository.

  * The version of darcs should be 2.10.1 or later.

  * There should be a working sendmail binary under /sbin, /usr/sbin, or in
    the default PATH.

Files:

  .darcs-notify-template  A text file in email format, containing at least
                          one To:  and a Subject: header; the
                          latter should mention the name of the repo. It
                          makes sense to keep this file under version
                          control inside the repo under consideration.

  .darcs-notify-log       Temporary file containing the darcs log of the
                          current patch.

  .darcs-notify-patches   Temporary file containing information about all
                          patches of the current operation (in xml format).

  .darcs-notify-lock      Temporary file used for locking.