This program does some monte carlo testing of both naive and
consistent hashing of keys to sharded caches of a database.  Run
without the -d argument, it first prints out the overall hit ratio for
naive hashing and then the overall hit ratio for consistent hashing,
after doing several random tests.  One can control various sizes and
measures with command line arguments, but the defaults will nearly
always show how consistent hashing is better.  Run with the -d
argument, many more details about what the program is doing are
printed.