Issue #76 build binary for Windows x64

build with node-gyp@0.9.5, node@0.10.3, Visual Studio 11 on Win 8

Test:
```javascript
> var sass = require('node-sass');
> sass.render('body{background:blue; a{color:black;}}', function(err, css){
...   console.log(css)
... }/*, { includePaths: [ 'lib/', 'mod/' ], outputStyle: 'compressed' }*/);
> body {
  background: blue; }
  body a {
    color: black; }
```