Implement basic Map Singleton

[krogenth]

We'll want to keep a record of the entire map state. This map will be a singleton, only one instance of a Map should ever exist at any time. This task only deals with regards to map initialization and tiling, no units/resources. The Map should be capable of resetting between matches, and should be called in the bot Module's onStart() or onEnd().

This includes:

• records of each tile on the map, see Implement basic Map Tile class #1
• storing the map size in terms of Implement basic Map Tile class #1 Tile size, store in a BWAPI::TilePosition

functionality:

• capability to draw all Tiles to the game map
• capability to return a const references to the underlying tiles
• capability to return a const reference to the map size

For more information on the Singleton design pattern: https://stackoverflow.com/questions/1008019/c-singleton-design-pattern