Slime Chunk to Seed Finder

This relies on weaknesses in Minecraft's algorithm to determine where a hostile
creature, slimes, can spawn. This pattern is determined by the secret "seed" value
of the world.

To compile this you will need:

  * gcc (tested with 4.6.3)
  * pthreads support

The tool can be compiled with GCC by running:

    make all

This is normally packaged with the parser pre-generated. To make from a clean git
repository, you will also need:

  * Ragel: http://www.complang.org/ragel/

You should then add a list of chunks where slimes are known to spawn *below Y level
40* to the file "chunks.txt". Don't include places where they appear in swamps above
Y level 40. These should be definite observations - adding a chunk where they don't
spawn will throw it off.

From there, you can run it with:

    make run

The file output.suffixes will be filled with at most 10,000 possible values for the
lower 48 bits of the seed. If there are more than 10,000 possibilities it will
be cut short. You can get a full output (may be extremely large) with:

    ./slime_seed > output.suffixes

The map of how likely each chunk is now to spawn slimes will be output as a map
file in map.png (map.pgm if "convert" utility from imagemagick not found). Each
pixel corresponds to a chunk, and indicates the likelihood of spawning slimes from
black representing zero to pure white representing 100% chance.

If the seed was randomly generated by the Minecraft server itself (rather than
supplied externally) then there will be relatively few possible 64-bit seeds for
any given lower 48 bits. This is because it only uses 48 bits of entropy when
selecting a random seed. The file likely.seeds will contain these expanded 64 bit
seeds.