TMSS-605: Add check for stations in use when saving reservation, and fix reservations tests which were a no-op so far

TMSS-955: fixed the dependency issues. We need to upload/populate the templates from a client, which means that tmss itself must be up and running (and migrations are done). After that, the taskconnectortypes can be populated. And after that the permissions. The latter needs direct dajngo access, so as a result the tmss_populate program now has both an http rest client and direct djanog access.

TMSS-682: Get the t_reservations module from TMSS-668 and move testcase from t_tasks to the correct module, t_reservations

TMSS-668: Move retrieving of active station reservations function from dynamic scheduler to separate reservations module. Add unittests for reservations module. Add stop_time in Reservations model, and calculate duration (it was visa versa)