[dovecot/core] f97dce: notify-status: Add notify-status plugin

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: f97dcee675e94c4a8ce17506e2c52ff5f1e81cf5
      https://github.com/dovecot/core/commit/f97dcee675e94c4a8ce17506e2c52ff5f1e81cf5
  Author: Aki Tuomi <aki.tuomi at dovecot.fi>
  Date:   2017-07-05 (Wed, 05 Jul 2017)

  Changed paths:
    M configure.ac
    M src/plugins/Makefile.am
    A src/plugins/notify-status/Makefile.am
    A src/plugins/notify-status/notify-status-plugin.c

  Log Message:
  -----------
  notify-status: Add notify-status plugin

This enables updating a dictionary with mailbox
status information when the mailbox changes.

It requires notify_status_dict setting for specifying
the dict where the data is stored.

One can optionally use notify_status_mailbox patterns
for specifying which box(es) the status update is done.
Subsequent patterns are notify_status_mailbox2 and so forth.

One can also specify data format using notify_status_value
plugin setting.