Bug 1039465 - [Contacts DataRefactor] Tweak global_contacts_data module ...

...and multi_contact
With the change above this would become:

```javascript
var _getEntriesData = function(ids) { // We could give this one a different name
  return getEntry(ids).then(function success(entries) {
    return entries.map(function(entry) {
      MultiContact.getData({
        id: globalDsId,
        entryData: entry
      }));
  });
};

var getData = function getData(globalDsId) {
  return _getEntriesData(globalDsId).then(function success(entry) {
    return entry[0];
  });
}
```