Actived alternative threaded implementation.
Compile only one of the two threaded versions.
Excluded more irrelevant code for partition_threading.
Completed stream based threading of when sorting buckets.
Started to synchronize the results computed by the threads.
Buckets sorted by threads are finally synchronized.
Moved mutexes into the structure they protect.
Satisfy compile and src_check
Merge pull request #235 from stefan-kurtz/sk

Add some code related to threading of suffixerator; cosmetics