output rdat if it has an extra band at 3 end, corresponding to full-length extension; now updates offset, sequence, and structure. Get rid of additional tab after SEQPOS.
output rdat if it has an extra band at 3 end, corresponding to full-length extension; now updates offset, sequence, and structure. Get rid of additional tab after SEQPOS.

hitrace/RDATKit,hitrace/RDATKit