Native unit tests should be mocking

[miwong]

The native unit tests for the extensions (e.g. blackberry.connection) currently do not use mocking. We should add mocking tests to fully test the code.

This would require the structure of the classes to change a bit. Namely, we would either need to make functions virtual or we would need to split interface/implementation by having our classes inherit purely abstract base classes. In addition, to mock BPS functions, we may need to create a new class that would be used to access these functions. We can then mock the BPS functions by mocking this class.