Fix crash when saving level on Windows; New texture for dirt and grass; Add GlassBlock; Easier texture index use in code; Fix issues detected by IDE Code Analysis

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  I also added GlassBlock, which is exactly what the name implies, and a new function to assist in getting texture indexes.  Code Analysis detected and fixed several minor issues, and I encountered no problems with the fixes.