improved StaticFlowEntryManager

Two modifications

A. 'ip_proto' field in match can be a hexa or decimal format.

B. 'reload' REST API is divided into two types.
  - reload all flow entries : /wm/staticflowentry/reload/all/json
  - reload flow entries into a specified switch : /wm/staticflowentry/reload/{DPID}/json
  - Old version supports the former only : /wm/staticflowentry/reload/json
Because all REST API are published already, it is needed a careful choice.