Editor's save-feature now uploads the game to the server

Pressing the save-button now uploads the game to the server.
There are still some bugs that need to be fixed. It looks like
saving the game once and restarting the editor breaks something,
since in that scenario the game can't be saved again.

Also added some comments to Client.py, removed some deprecated
debugging / learning-to-do-stuff functions, and cleaned up tests.py
Currently there's no tests available, and I really don't know if
I'll add any.