AssetRewrite.rewriteAssetPath incorrectly matching remote file paths containing the same name as a valid rewrite

As described in this [S.O. issue](http://stackoverflow.com/questions/32320529/ember-cli-build-fingerprinting-external-url), if there is a remote file path that contains the same filename as another file that is a valid rewrite (an actual asset path that should be rewritten), the rewriteAssetPath method is processing those paths even though they're to a remote path.

For instance, in a project named `coolapp`:

``` js
model: function() {
// this path is being rewritten because it's matching `coolapp` but not taking into account that it's from a remote path
return Ember.$.getJSON('http://my.remote.url.com/coolapp.json');
}
```

I imagine this probably just needs some adjustments to the regex to prevent matching remote paths.