pidgin/pidgin

Make our windows builds usable from meson.
release-2.x.y
2021-04-19, Gary Kramlich
2ff89178eb3d
Make our windows builds usable from meson.

This creates our pkg-config files on windows as well as fixes an include in
pidgin.h which can cause some issues.

This isn't usable as is, as you need a machine-file and a pkg-config wrapper
to make this all work, but that will be updated in the win32-dev.7z file thats
on data.imfreedom.org.

Testing Done:
Compiled guifications2 (which now uses meson) on windows and verified it works.

Reviewed at https://reviews.imfreedom.org/r/615/
/** @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