My implementation of applet settings

I still need to find something to avoid two applets using the same name for a key, maybe adding the applet's name to the key's name.

In JS code, you can use global.get_applet_setting("name of key") to read settings,
global.set_applet_setting("name of key", value) to set something,
where value is a string.

If a key does not exist, NULL is returned when trying to read it.