Performance boost and Map Textures

Finally fixed the crash bug. And I can add textured map sprites, too.

Before this update, running this game on Firefox would crash after about 20 minutes. Chrome wouldn't crash but instead would play at around 15 fps. Turns out drawing all of those hexagonal tiles are CPU intensive and the browsers can't keep up.

Each terrain type now uses an image. Turns out drawing an image is much less intense. And it looks nice as long as you line up the seams correctly.