Ability to control network parameters for flavors

To add extra specification(network bandwith, ...) to the flavors, administrators have to set the specs via command line.
We can add network parameters (inbound_average, inbound_peak, ...) to the flavor 'Create' form.
Two approaches existed:
1- Add network parameters as a form field(A form field per spec).
2- Add ExtraSpec form field(textbox) to allow admins write their own key values(requirement_bandwidth: 1000).