old_contents: {
  	'targets': [
  		{
  			'target_name': 'uwrap',
  			'sources': [
  				'src/uwrap.cc',
  			],
  			'cflags': [
  				'-Wall',
  			],
  			'include_dirs' : [
  				"<!(node -e \"require('nan')\")"
  			],
  		},
  	],
  }
  
new_contents: {
  	'targets': [
  		{
  			'target_name': 'uwrap',
  			'sources': [
  				'src/uwrap.cc',
  			],
  			'cflags': [
  				'-Wall',
  			],
  			'include_dirs' : [
  				"<!(node -e \"require('nan')\")"
  			],
  			'xcode_settings': {
  				'MACOSX_DEPLOYMENT_TARGET':'10.7',
  				'OTHER_CFLAGS': [ '--stdlib=libc++' ],
  			},
  		},
  	],
  }
  
subject: add osx build flags