Scala 2.10.2, Custom Code 0.6.3

This brings the local dev environment up to the current Custom Code SDK version, ~~0.6.2~~ 0.6.3. 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:

* [x] Find an appropriate way to implement `countObjects` and `deleteObjects`
* [x] Implement them
* [x] Update examples to reflect SDK updates, deprecations, etc.
* [x] release StackMob Java SDK 1.3.7