Make "About" always enabled for plugins

[birdie-github]

The About button for plug-ins is in the disabled state unless the plugin is enabled which is kinda counter-intuitive since you may want to learn what the plugin does before enabling it.

[mschwendt]

Why not enable it and disable it again? Quick and efficient.

To access the plugin information dialog, Audacious would need to load a plugin. It sounds cumbersome to do that for all plugins, even if a different implementation might only cache that information for later use. Also, for most plugins that button doesn't tell what the plugin does, but it only displays credits and possibly the licensing.

[birdie-github]

To access the plugin information dialog, Audacious would need to load a plugin.

Plugins are already sort of loaded on start-up.

It sounds cumbersome to do that for all plugins, even if a different implementation might only cache that information for later use.

This can be done on a per-plugin basis or the plugin API could be changed to avoid this altogether.

Also, for most plugins that button doesn't tell what the plugin does, but it only displays credits and possibly the licensing.

And that's just bad and should be fixed as well.

[mschwendt]

Once registered, a known but disabled plugin won't be loaded.