Save token to localStorage

Save token to localStorage as well as $cookieStore to support sites running in local filesystems with no cookie support (e.g. inside cordova apps).
@perry @henrahmagix What about:
```
$cookieStore.put('auth', {
    token: token
});
if (!angular.isDefined($cookieStore.get('auth'))) {
    // save to localstorage...
}
```

You could do that check once when the service loads to save some performance, but `setToken` doesn't run that often?