message: build: enable /MP flag when building on Windows
diff: # 4506 and 4838 -> about v8 inline function and narrowing
  # 4068 -> Unknown pragma (mostly GCC pragmas being used)
  # 4996 -> Declared wrongly Nan::Callback::Call
  - 'DisableSpecificWarnings': ['4244', '4506', '4068', '4838', '4996']
  + 'DisableSpecificWarnings': ['4244', '4506', '4068', '4838', '4996'],
  + 'AdditionalOptions': [
  + '/MP', #compile across multiple CPUs
  + ],
  },
  'VCLinkerTool': {
  'GenerateDebugInformation': 'true',
  'OmitFramePointers': 'true',
  'EnableFunctionLevelLinking': 'true',
  'EnableIntrinsicFunctions': 'true',
  - 'WarnAsError': 'true'
  + 'WarnAsError': 'true',
  }
  }
  },
  