Add notes about lack of validation when values are set into SAMRecord.
Add notes about lack of validation when values are set into SAMRecord.

annkupi/picard,nh13/picard,annkupi/picard,alecw/picard,annkupi/picard,alecw/picard,nh13/picard,broadinstitute/picard,annkupi/picard,alecw/picard,alecw/picard,nh13/picard,broadinstitute/picard,broadinstitute/picard,broadinstitute/picard,broadinstitute/picard,nh13/picard