Nicolas Dufresne authored Oct 30, 2014 and Olivier Crête committed Feb 25, 2015

This required change FS_INIT_PLUGIN() macro. It's now taking name and
type argumenet. This is a slight API break, but there never existed any
external plugins. Also, already built plugins should not be affected since
the symbol remains the same.

Note also that plugin are no longer unloadable, it was already not well
supported. Instead of adding loads of if, we simply register the module
types as static (just like GStreamer does).

To register static plugin, you can declare it's registration function
using FS_PLUGIN_STATIC_DECLARE(name), and then in your code call the
function using FS_PLUGIN_STATIC_REGISTER(name).

https://bugs.freedesktop.org/show_bug.cgi?id=89287