fs.exists is bad example for docs

[ex1st]

https://nodejs.org/dist/v4.2.2/docs/api/fs.html#fs_fs_exists_path_callback
Stability: 0 - Deprecated: Use fs.stat or fs.access instead.

Now all async functions without error in callback are deprecated (node.js). Need to change examples.
I also suggest change methods like filter and reject in 2.0 for consistency with node.js practics.

async.filter(['file1','file2','file3'], function (file, cb) { 
    fs.stat(file, function(err, stat){
        cb(null, !err);
    });
}, function (err, results) {
    // results now equals an array of the existing files
});

What do you think?

[aearly]

We're going to change how these functions work in the next major release: #118 . As they exist today, fs.exists is just about the only function that's useful for these methods.

[ex1st]

Ok, thanks.