Changed the data types for the sdb class characters to be unsigned

Changed the data types for the sdb class characters to be unsigned
characters; this fixed a bug that prevented the arguments to a function
from being printed symbolically.  The fix was done globally; it is not
known if the "fix" fixed other bugs

SCCS-vsn: old/sdb/access.c 4.2
SCCS-vsn: old/sdb/decode.c 4.2
SCCS-vsn: old/sdb/display.c 4.3
SCCS-vsn: old/sdb/docomm.c 4.2
SCCS-vsn: old/sdb/fio.c 4.2
SCCS-vsn: old/sdb/main.c 4.2
SCCS-vsn: old/sdb/message.c 4.2
SCCS-vsn: old/sdb/old.c 4.2
SCCS-vsn: old/sdb/pcs.c 4.2
SCCS-vsn: old/sdb/prvar.c 4.3
SCCS-vsn: old/sdb/rdwr.c 4.2
SCCS-vsn: old/sdb/re.c 4.2
SCCS-vsn: old/sdb/runpcs.c 4.2
SCCS-vsn: old/sdb/setup.c 4.3
SCCS-vsn: old/sdb/sub.c 4.2
SCCS-vsn: old/sdb/symt.c 4.3
SCCS-vsn: old/sdb/udef.c 4.2
SCCS-vsn: old/sdb/version.c 4.2
SCCS-vsn: old/sdb/xeq.c 4.3
SCCS-vsn: old/sdb/cdefs.h 4.2
SCCS-vsn: old/sdb/defs.h 4.2
SCCS-vsn: old/sdb/head.h 4.3
SCCS-vsn: old/sdb/mac.h 4.2
SCCS-vsn: old/sdb/machine.h 4.2
SCCS-vsn: old/sdb/mode.h 4.2
SCCS-vsn: old/sdb/old.h 4.2