More logging from Scheduler, and detector mode changes.

[arnoldandreasson]

The detector tells when recordings are started and stopped, both in the log files and in the user interface. But the reason for this is not logged. Reasons may be that the user changed detector mode or that the scheduler activates/deactivates recording. This kind of information is useful when preparing the reports after a survey, as well as for debug purposes.

The main control loop for this is located in the Scheduler section and every 10 seconds it is checked whether recording is to be activated or deactivated.

[arnoldandreasson]

More logging is added.
Checked in to the master branch for testing.