pidgin/purple-plugin-pack

Use the meson summary instead of manually building our summary with message

Testing Done:
Ran `ninja reconfigure` and verified the output.

```
purple-plugin-pack 2.8.1dev

libpurple
install directory: /usr/local/lib/purple-2
data directory : /usr/local/share
plugins : autoreply, bash, capsnot, colorize, dewysiwygification, dice, eight_ball, flip,
google, groupmsg, highlight, ignore, irc-more, irchelper, listhandler, ning,
oldlogger, omegle, showoffline, simfix, slashexec, snpp, splitter, sslinfo,
translate, xmppprio

pidgin
install directory: /usr/local/lib/pidgin
data directory : /usr/local/share
plugins : album, blistops, convbadger, difftopic, enhancedhist, gRIM, icon-override, irssi,
lastseen, listlog, mystatusbox, nicksaid, plonkers, schedule, sepandtab,
switchspell, timelog

finch
install directory: /usr/local/lib
data directory : /usr/local/share
plugins :

User defined options
backend : ninja
```

Reviewed at https://reviews.imfreedom.org/r/2408/
/*
* Purple Plugin Pack - GLib Compatibility Header
*
* This code borrowed from GLib (http://www.gtk.org/) for backward
* compatibility with ancient versions of GLib.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02111-1301, USA.
*/
#ifndef PP_GLIB_COMPAT_H
#define PP_GLIB_COMPAT_H
#include <glib/gi18n-lib.h>
/* This space is reserved for future compatibility helpers */
#endif /* PP_GLIB_COMPAT_H */