add not_symmetric_scores selfbit=bitscore/qselfbit and otherbit=bitscore/tselfbit to lib/ClusterFuncs.py
improvements to printing and ordering for db_listDbFiles.py, now searches only executable files
machine-readable output option for db_listDbFiles.py
fixed bug in db_listDbFiles.py when -s or -w with a low number passed w/ a search that returns null