Several developers have pointed out to me that SAVE and RESTORE DATASESSION are useful especially in WebViews generated by rsp pages. It was however awkward to nest the saving and restoring properly. So in 2.1 I have added two new commands PUSH DATASESSION and POP DATASESSION. These operate in the same way as SAVE and RESTORE DATASESSION but enable pushing and popping data session state (database, tables, and cursor state) up to 256 levels deep.
