GASMemberOrder code Refactoring: tot_price --> price_expected
Fixed ParamRole.objects.get_param_role wrong use in gas manager.

By passing params as non keyword arguments, the following exception was given:

TypeError: get_param_roles() takes exactly 2 arguments (x given)
Fixtures to load in tests enviromnment.
Completed first phase of the order and intergas tests.

Started the integration of the client into the GAS tests.
Integrated views support to manage simple and ajax requests (including exceptions handling).
Fixed small bug due to distraction :)
Restored initial_data fixtures where needed.
Updated remote branch for submodule simple-accounting