pidgin/pidgin

Use LT_LIB_M to determine if we need to link to the math library and link Pidgin to the X11 libraries
release-2.x.y
2021-04-11, Gary Kramlich
132d17234930
Use LT_LIB_M to determine if we need to link to the math library and link Pidgin to the X11 libraries

Gentoo ran into an issue with the gold linker without -lm. The original patch
and work came from Justin Lechner. https://bugs.gentoo.org/386079

Gentoo also ran into an issue with X11_LIBS not being added to pidgin. This
should already be implicit everywhere except for homebrew which patches X11
out of their build. Original patch/work came from and. https://bugs.gentoo.org/500762

Testing Done:
Installed and ran locally.

Reviewed at https://reviews.imfreedom.org/r/608/
/** @page plugin-signals Plugin Signals
@signals
@signal plugin-load
@signal plugin-unload
@endsignals
@see plugin.h
<hr>
@signaldef plugin-load
@signalproto
void (*plugin_load)(PurplePlugin *plugin);
@endsignalproto
@signaldesc
Emitted when a plugin is loaded.
@param plugin The plugin that was loaded.
@endsignaldef
@signaldef plugin-unload
@signalproto
void (*plugin_unload)(PurplePlugin *plugin);
@endsignalproto
@signaldesc
Emitted when a plugin is unloaded.
@param plugin The plugin that was unloaded.
@endsignaldef
*/
// vim: syntax=c.doxygen tw=75 et