New exploration mini-game.

This week I worked on implementing the new exploration mini-game. Once you enter a sector and decide to explore it, you will see a small section in the middle of the screen where you will be able to direct your explorer to discover what the sector contains.

Besides finding entities like in the previous version, you will also find new terrain tiles, for now they only show graphics, but in the near future they will have different effects on the explorer. That way it will be more interesting to explore, having to evade some terrains that are hard or dangerous to traverse. Some could be too hot, like lava, or be walls that can be climbed with the right tools.