OverrideAPI v0.1

 *It becomes powerful*

You can:

1) Add buttons! You can add a button to GuiScreen without overriding or editing its class.

2) Override a GuiScreen so your one appears instead of original.

3) Override a vanilla block with your one.

NO base class is edited. This API should be compatible with anything.

Feel free to use it in your mods! :D

Credit:

- mine_diver

- rek (thanks for that trick with selectedButton, now I don't need to override the whole mouse input proccess xd)