Tweaked string output to show shape in repr() and include dump period for convenience in str().
Tweaked string output to show shape in repr() and include dump period for convenience in str().

git-svn-id: 88c9ca70625627825018ef89be83f0d41a8e4cf1@15825 b56c7a7d-ac47-0410-a905-b6f7de78896a

ska-sa/katdal