Add autosaving to the editor (#688)

* Add autosaving to the editor

* It saves the subtitle, tags, and license now

* Save the cover too

* Fix broken autosave again

* Use set_value instead of a multitude of setters. Implement debouncing

* Remove unsafe code, remove generic getters when possible

plume-front/src/main.rs

@@ -8,7 +8,8 @@ extern crate gettext_macros;
 extern crate lazy_static;
 #[macro_use]
 extern crate stdweb;
-
+extern crate serde;
+extern crate serde_json;
 use stdweb::web::{event::*, *};
 
 init_i18n!(