KEYLINE indicates which contour lines to process based on VGTYPE
KEYLINE = 0 - process all line types
KEYLINE = m/n - process all lines with VGTYPE m and SUBTYP n
m is the VGF Object type and can be
LINE or SPLN (special line type).
n is the GEMPAK code number for a specific
object type within VGTYPE. See
$GEMTBL/pgen/setting.tbl for code numbers.
KEYLINE=SPLN/4 will process only pointed arrowed lines.
KEYLINE=SPLN/3 will process only scalloped lines.