fix (graph.graph component.legend) uses data state when component update()/redraw
refactor (examples.component-legend) needs datacollection to work
test (graph.graph-builder) show/hide series data state maintains on update
test (graph.spec legend.spec) unit tests for show/hide data-state
Merge pull request #124 from racker/data-state

fix (graph.graph component.legend) uses data state when component update()/redraws