Scala 2.10.2, Custom Code 0.6.2

This brings the local dev environment up to the current Custom Code SDK version, 0.6.2. This entails extending the DataServiceImpl, which itself will entail external updates to the StackMob Java SDK or equivalent API changes. Following that, two DataService methods need to be implemented: `countObjects` and `deleteObjects`.

So, to complete this pull request, it will be necessary to:

* [ ] Find an appropriate way to implement `countObjects` and `deleteObjects`
* [ ] Implement them
* [ ] Update examples to reflect SDK updates, deprecations, etc.