inserts at the cursor position for n times the last non-empty line
that was deleted with the
DeleteLine command. If n is not
specified, it is assumed to be one.
UndelLine is most useful in that it allows a very fast way of moving
one line around. Just delete it, and undelete it somewhere else. It is
also an easy way to replicate a line without getting involved with clips.
UndelLine works independently of the status of the
undo flag. See DoUndo.