Remember player position

[snipercup]

When loading a game, you start at 0,0 instead of the position you exited the game from.

I think the implementation should be something like:

• As soon as the player spawns, move him to the position from the save file
• Start loading chunks around the player. Freeze the player if needed so he doesn't fall before the chunks are loaded
• Additionally, update the overmap to center on the player position