Thunderstorm v1.2

  - Update: Sharper lightning bolts
  - New Feature: Minimalist Mode

Minimalist mode is actually a bit of an off-the-cuff feature in response to an e-mail asking if they could get just the lightning against a black background.  As it's easy to do, why not?

The lightning bolt graphics are now double the resolution, with some tech development done to offset the memory usage.  While previously all images were treated as RGB, now the engine supports loading of greyscale TGA images, and will appropriately treat them as luminance at upload time.  That means while the image is much higher res, it should actually be using a comparable amount of memory to before.

Notably, while the glTexImage2D description says input format and internal format are supposed to be separate, and that it's OpenGL's responsibility to convert from one to the other, I didn't find that to be the case on my HTC device.  Whatever your input format is dictates your internal format, so far as I can tell.  I suspect the internal format argument is more or less ignored.