Solve inconsistency between network graph & stat graphs

app/controllers/graphs_controller.rb

app/controllers/network_controller.rb

app/controllers/refs_controller.rb

app/views/graphs/show.html.haml

app/views/graphs/show.js.haml

app/views/layouts/nav/_project.html.haml

app/views/network/_head.html.haml

app/views/network/show.html.haml

app/views/network/show.json.erb

config/routes.rb

features/steps/project/project_graph.rb

features/steps/project/project_network_graph.rb

features/steps/shared/paths.rb

spec/routing/project_routing_spec.rb