better simulation life cycle implemented for test_simulation_control. The errors that remain correpsond to a different behavior between the mock backend and the other backends, and could correspond to bugs. Note that test_connectors has been excluded, as it extensively tests the MPI and I am still looking at the error it induces. For test_connectors, I have to improve the current framework.
include a sim.__name__ == mock is test_population and test_populationview. It is not satisfactory: I will build a new test
previous hack corrected. unittests and backend unittests now correctly separated. Bug in alias for test_assembly corrected
test_projection added. Correction of simulation life cycle in test_population and test_populationview