Added support for Minecraft Classic !

[ExplodingBottle]

Hello,
This pull request contains a lot of code for Minecraft Classic support !

This support adds these features:

• Now support custom resolution on startup. ( Not when launched ) using --width width and --height height options.
• Added a way to toggle survival on or off on startup. using --survival.
• Resources now load ! You can now hear music and any kind of noises in game.
• Minecraft Classic doesn't freeze anymore when closing game window.
• You can now save and load your worlds again !
• Allowing to connect to multiplayer servers. using --server adress:port option.
• UUID is now exploited as mppass. you need to add ${auth_uuid} as third argument.

I've made this pull request in the hope that it will be helpful !