... from table cursor.  The problem is that in this case, between
Push() and Pop() there is no call to ClearMark() or any of the other
functions that sets the SwTableCursor::m_bChanged flag, so MakeBoxSels()
is never called for the m_pCurrentCursor after Pop() and there is no
cursor ring selecting all table cells.

(regression from b227a8e4)

Change-Id: I5bce18b71fed60a926f4ddf9938dfb7d1ddf4e92