fix #8507

made void connectNotify( const char * signal ) protected instead of private
made bool eventFilter( QObject *obj, QEvent *event ) protected instead of private
made void showEvent( QShowEvent * ) and void hideEvent( QHideEvent * ) instead of private
apply #8601
fix gui bindings with SIP 4.15
revert change of doxygen DOT_GRAPH_MAX_NODES
debian packaging: add jessie and saucy