Simplify FlowSpace selection through Expedient OpenFlow plug-in

[CarolinaFernandez]

• Instead of returning 2-3 forms to let the user choose a FlowSpace, only one should be shown
• User should be able to request additional FlowSpaces, one at a time (i.e. "Define another FlowSpace")
• Saving of the FlowSpaces data should be automatically done when exiting this screen (i.e. "Save and exit" instead of "Done")