Loads plugin. Note that the *return value* is the loaded plugin; plugin is untouched. The normal use pattern of this function goes like this:

|[ GstPlugin *loaded_plugin; loaded_plugin = gst_plugin_load (plugin); // presumably, we're no longer interested in the potentially-unloaded plugin gst_object_unref (plugin); plugin = loaded_plugin;

Returns: a reference to a loaded plugin, or
    `NULL` on error.
class Plugin