Added parameters to 484 mapping:
http://com1software.com/c1d0m484.htm#0634
P = Previous Segment
Checks an 8 segment buffer for a valid segment and
qualifier.
Q = Previous Segment Qualifier
R = Previous Segment Qualifier Position
S = Toggle Off Field
Turns off field population if this field is populated
Improved mapping for 271
Improvements in 837I mapping