TODO:

* Multiprocess capabilty using either:
   - threads
   - multiple instances using shared memory to share a cache
   - Asynchronous via asio or libevent
* ICC profile integration via lcms library
* Lossless Rotation / transposition support for JPEG tiles
* JPEG source image support
* Look into using malloc_usable_size to trace real allocated space
* Lanczos, bilinear etc interpolation for CVT
* Copy EXIF, IPTC data for CVT exports
* Optimize FIF code for very large files
* Rewrite JPEG writer code for better buffered output