Fix crash when saving level on Windows; New texture for dirt and grass.

First thing I noticed when running the game is that it crashed every time it tried to save the level.  I was able to fix this by adding a direct call to File.createNewFile() if the file being saved does not exist.  I also slightly adjusted the textures for dirt and grass:  Grass has light speckles and had red and blue values slightly increased, and grass has very light speckles to help with tiling.  [Here](http://imgur.com/a/abIwF#0) are some screenshots of the new colors. http://imgur.com/a/abIwF#0