quiva2DB, DB2quiva, and QV support

The compression and decompression codes in DEXTRACTOR/dexqv.c and
undexqv.c have been refactored into a library QV.c and QV.h that is now
“intertwined” with the core support of DB.c and DB.h.

DB.[ch] now has routines to support QV’s within the database.  DBshow
in particular uses these routines to display QV information when
requested.

quiva2DB and DB2quiva that import and export QV information into and
out of a database are now implemented.

-v flags added to fasta2DB, DB2fasta, and Catrack.