Version 0.2:

- Added support for 16-bit data (RGB, RGBA, Grayscale and Gray+Alpha
  color types)

- Added support for packed 1-, 2- or 4-bit pixels (Grayscale and
  Indexed colors)

- Fixed interlace handling code which was severely broken

- Added possibility to process images without reading the entire image
  into memory

- Internals are refactored while the client interface is mostly
  unchanged

- Added intensive test suite

- Added documentation
