pidgin/pidgin

Install our appdata file to $(datadir)/metainfo as that change was made a long time ago

This patch originates from Lars Wendler from Gentoo

https://gitweb.gentoo.org/repo/gentoo.git/commit/net-im/pidgin/files/pidgin-2.13.0-metainfo.patch?id=2dd6c1852251b5b67c3045badf173be9535b97a9

Testing Done:
Installed to a prefix and verified the file ended up in `$prefix/share/metainfo`

Reviewed at https://reviews.imfreedom.org/r/607/
/** @page log-signals Log Signals
@signals
@signal log-timestamp
@endsignals
@see log.h
<hr>
@signaldef log-timestamp
@signalproto
char *(*log_timestamp)(PurpleLog *log, time_t when, gboolean show_date);
@endsignalproto
@signaldesc
Emitted to allow plugins to customize the timestamp on a message
being logged.
@param log The log the message belongs to.
@param when The time to be converted to a string.
@param show_date Whether the date should be displayed.
@return A textual representation of the time, or @c NULL to use a
default format.
@note Plugins must be careful of logs with a type of PURPLE_LOG_SYSTEM.
@endsignaldef
*/
// vim: syntax=c.doxygen tw=75 et