Changed some textures to match tileset size. Added the concept of map cells which make up the tile map. Each map cell can contain dead zones, path nodes, and tiles. Dead zones are used to detect when nothing can be placed or pathed through it (walls, etc). Path nodes are used to determine where agents can path between other agents. Tiles are used to draw textures like walls and objects. Changed pathing to work explicitly with path nodes based on world positions instead of world grid indices. Changed closest path algorithm to check actual best path rather than manhatten distance. Refactored TiledMap classes into separate class files to reduce confusion.