qulogic/gplugin

A few updates to cleanup a bunch of code in libpurple.
feature/unload-failed-state
2020-04-10, Gary Kramlich
5a05c6354d62
A few updates to cleanup a bunch of code in libpurple.

* Add a new plugin state UNLOAD_FAILED that tracks when a plugin failed to
unload.
* Add a new signal GPluginManager::unload-plugin-failed
* Update GPluginManager::load-failed to pass the error, if any, that the
plugin returned.
* Added gplugin_manager_foreach and GPluginManagerForeachFunc to make it
easier to operate on all plugins.
# Dependencies
GPlugin depends on the following at a bare minimum:
* glib-2.0 >= 2.40.0
* gobject-introspection, libgirepository1.0-dev
* meson >= 0.42.0
* gettext
* help2man
* a C compiler
A full build (enabled by default) depends on the following:
* gtk-3
* python3-dev, python-gi-dev, python3-gi
* liblua5.1-0-dev, lua-lgi
* valac
All of these packages and their development headers need to be installed
prior to building GPlugin.
# Building
GPlugin uses meson (http://mesonbuild.com/) as its build system. As such
compiling is a little bit different than your typical `./configure`, `make`,
`sudo make install`.
Meson requires you to build in a separate directory than your source. As such,
these instructions use a separate build directory.
To compile you need to run the following commands:
```
meson build
cd build
ninja install
```
If you want/need to tweak the build system (to enable/disable certain loaders)
you can do so at any time by using `meson configure` in the build directory.