Arc Map is designed to allow a HashMap of Arc<Mutex<T>> to be stored in such a way that elements can be accessed without the need to lock the whole Map while you have access to them.
Contributions Welcome
changed on_do to take a &self, instead of &mut self on_do now take FnOnce, as it will only call it once.
changed &mut self to &self, in three main methods. making it much easier to use as part of another object.
Switched main channel to SyncSender, for sync in parents