Switch: MACAddressTable changes:

- Now it uses std::map for efficient Address Table search and access
- Some major renaming: registerMAC -> updateTableWithAddress,
  resolveMAC -> getPortForAddress, etc.
- Some parts of code are based on MACRelayUnitBase.
- resolveMAC/getPortForAddress: outputPorts removed from parameters
  as it is not needed because getPortForAddress always returns a
  single port.