gplugin/gplugin

Add gir targets to the dependencies sources attribute and other meson cleanups.

2021-09-25, Gary Kramlich
476c9cac712b
Add gir targets to the dependencies sources attribute and other meson cleanups.

Adding the gir targs to the dependency object of the library allows us to be
able to use the dependency in a gnome.generate_gir for a library that consumes
our api regardless of if it's a system install or a subproject.

Testing Done:
Modified the gplugin subproject in pidgin and used these changes to verify that it fixed the current build issues over there.

Reviewed at https://reviews.imfreedom.org/r/939/
# GPlugin
[ ![Download](https://api.bintray.com/packages/pidgin/releases/GPlugin/images/download.svg) ](https://bintray.com/pidgin/releases/GPlugin/_latestVersion)
[ ![Issues](https://img.shields.io/badge/Issues-YouTrack-ee3b8b.svg) ](https://issues.imfreedom.org/issues/GPLUGIN)
GPlugin is a GObject based library that implements a reusable plugin system.
It supports loading plugins in multiple other languages via loaders. It relies
heavily on [GObjectIntrospection](https://gi.readthedocs.io/) to expose its API
to the other languages.
It has a simple API which makes it very easy to use in your application.
For more information on using GPlugin in your application, please see the
[embedding](https://docs.pidgin.im/gplugin/latest/chapter-embedding.html) page.
## History
GPlugin has a bit of history, you can read more about it in [HISTORY.md](HISTORY.md)
## Language Support
GPlugin currently supports plugins written in C/C++, Lua, Perl5, Python3, and
Vala.
## API Reference
The in-development API reference for the development branch can be found at
[docs.pidgin.im/gplugin/latest](https://docs.pidgin.im/gplugin/latest/).