Major overhaul.

* Renamed project "comsat-mongodb" -> "comsat-mongodb-allanbanks" in order to stress the underlying
implementation (with dual-licence policy)
* Converted from partial wrapping approach to implementation subclassing and overriding approach. Previous
blocking methods exported by the original implementation are fiber-blocking in this subclassing
implementation. Interface compatibility is retained, so drop-in replacement becomes possible. Disadvantage is
that this implementation now depends on non-API (implementation) from the allanbanks driver
* Test classes structure in place together with first tests