Comment #8 on issue 884 by benjamin...(a)gmail.com: The Roassal presentation
should react to custom ports
http://code.google.com/p/moose-technology/issues/detail?id=884
Just a minor tweak... when clicking on the #index pane background,
'ann value' is nil, so need to wrap ROHighlightElement...
ann value ifNotNil: [ ROHighlightElement on: (ann presentation view raw
elementFromModel: ann value) color: Color red ]]]]]].