Start splitting the connectors module (extract the core interfaces)
Fix `target` folder creation
Implement new configuration library
Fix existing code to use the new configuration library (not tested yet)
Fix package names in logback configuration
Fix `PropertiesBackedConfigurationSource` to be compliant with old platform properties files
Add configuration related utilitary classes
Add new callback completion backend, a replacement for deferred futures
Start refactoring connectors (preparations for native connectors)

* Move interoperability-based connectors to a new sub-package `...connectors.interop....`.
* Better split the `BaseConnector` implementation (the asynchronous and enforcement wrapper) from it's proxy implementation (the actual logic).
* Refactor the KV connector to follow the new pattern.
Enhance configuration related classes
Refactor connector initialization code to allow transmitting the component connector via the environment

Currently this is a hack, and the "environment" and "configuration" classes will have to be heavily refactored.
Minor updates
First "compilable" Riak native connector (not tested yet)