refactoring so that a singleton of PathwayEnrichmentHighlghter can be
used; a bug fix so that highlighted FI network can be converted into a
pathway diagram that is highlighted still.
Mapping FIs and genes in a FI network view to a sub-pathway contained in
a corresponding pathway diagram
refactoring: moved code for event selection from PathwayInternalFrame to
CyZoomablePahtwayEditor; synchronize selection in three components:
tree, fi view and diagram view.