Set a maximum time between archived fits files

[g7gpr]

RMS stations provide good quality images of the sky. A feature could be added to provide a maximum time difference between fits files, so that if no meteor was detected for a greater period than that time, fits files would be brough in from the night_captured_dir.

In this way, for a small additional number of fits files, a comprehensive record of the night sky from each station could be held at gmn.uwo.ca