Eio Model: Created MVC (Model-View-Controller) for EFL.

We have few basic codes:
1 - Emodel Interface that can be found at src/lib/emodel. (emodel.eo plus headers)
2 - Eio Model - Model implementation for EIO in src/lib/eio. (eio_model.c plus headers)
3 - Also we have a simple test that can be found at src/tests/emodel which can be used to test both Emodel and Eio Model impl generating simple debug output.