old_contents: {
    'targets': [
      {
        'target_name': 'gpiobcm2835nodejs',
        'sources': [
          'src/gpiobcm2835nodejs.cc',
          'src/gpio_functions.cc'
        ],
        "cflags" : [ "-lrt -lbcm2835" ],
        'conditions': [
                  ['OS=="linux"', {
                    'cflags!': [
                      '-lrt -lbcm2835',
                    ],
                  }],
                ]
      }
    ]
  }
new_contents: {
    'targets': [
      {
        'target_name': 'gpiobcm2835nodejs',
        'sources': [
          'src/gpiobcm2835nodejs.cc',
          'src/gpio_functions.h',
          'src/gpio_functions.cc'
        ],
        "cflags" : [ "-lrt -lbcm2835" ],
        'conditions': [
                  ['OS=="linux"', {
                    'cflags!': [
                      '-lrt -lbcm2835',
                    ],
                  }],
                ]
      }
    ]
  }
subject: add new module