ktxtool now prints info from a KTX file's header.

Info includes:

- OpenGL "format"
- OpenGL "type"
- Image width
- Image height
- Image depth
- Number of mipmap levels
- Number of faces
- Array size
- For compressed images (not yet supported):
  - OpenGL internal format
  - OpenGL internal base format
  - Block dimensions
  - Bytes per block