LazReport, implemented export filter OnExported event to signal the view has been exported

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41012 4005530d-fff6-0310-9dd1-cebe43e6787f
LazReport, cairo exporter, enable clipping for memo views

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41013 4005530d-fff6-0310-9dd1-cebe43e6787f