Quick fix-up

Before getting any further, here's a quick fix-up with things that should have been on v0.13.5 but were missed. Specifically, the timeout when receiving a request will now work properly.

Some other additions are a tiny fix when handling updates, which was ignoring some of them, nicer __str__ and .stringify() methods for the TLObject's, and not stopping the ReadThread if you try invoking something there (now it simply returns None).