o.c.graphene: better handling of empty data formula
o.c.grapene: pushing most line graph and scatter graph code for the widget in the superclass
o.c.graphene.opiwidgets: fixing dependencies
Merge branch '3.2.x' of git@github.com:ControlSystemStudio/cs-studio.git into 3.2.x

Conflicts:
	applications/plugins/org.csstudio.graphene/src/org/csstudio/graphene/AbstractPointDatasetGraph2DWidget.java