Add work on parallel (threaded) lzjb utility
Process parallel data in large chunks
Further improve threaded compressor
Begin merging pthreads version and non-threaded version
Merge pthreads implementation, update/fix Makefile

POSIX threads have been added to the compression utility and are
enabled by default. This can be overridden by passing NOTHREADS=1
on the make command line. The Makefile has also been fixed to
enable use of parallelized make without errors.
Bump version date