ddefine allows restructure of to and from memo/blob field types.
Deleting the last line of a memo could cause a crash upon save.
If the only changes made to a record were via MEMO EDIT, those changes
would not be saved.
Fix *cabe DEL problems under Unix/Linux.
Memo editor now requires double-break to cancel.
Memo editor - when you marked text end-to-front, cut/copy would
crash.
Memo editor didn't find text at end-of-line.
"Toggle insert" added to memo editor F8/options menu.
Repeated use of the sequence MEMO DELETE, MEMO IMPORT, MEMO EDIT
while remaining within the processing, could corrupt the blob file.