Topology discovery is broken in Active/Active controllers

Topology discovery is broken in Active/Active controllers

    ISSUE: Edges which endpoints are managed by different controllers cannot be discovered
           This happens because Discovery discards LLDP frames coming from non-local node connectors
    CHANGES:
    - in processDiscoveryPacket():
      + do not discard LLDP frames coming in from non-local node connectors
      + after discovering an edge, put it in the timeout map (pendingMap) keyed by the incoming port (tail node connector)
    - in doDiscovery():
      + do not add local node connectors to the timeout map (pendingMap)
        This map now contains the time (ticks) elapsed since last LLDP frame was received on the respective node connector.
    - Some style and minor static analysis fix changes

Signed-off-by: Alessandro Boch <aboch@cisco.com>