Extended API endpoints.

src/rest/controllers/internal_controller.py

src/rest/controllers/public_controller.py

src/rest/models/clock_info.py

src/rest/models/play_log_entry.py

src/rest/models/timeslot.py

src/rest/swagger/swagger.yaml

src/rest/test/test_internal_controller.py

src/rest/test/test_public_controller.py