Example script: added lagging and fix

Added some print statements to follow what the script is doing.
By default, work with only one day of data.
Reverted a change which kept redoing the processing of events
Don't redo direction reconstruction
Master-single-station did not actually use coincidences
Sciencepark master.py works

And is a bit updated.
WIP: moved search_coincidences to SAPPHiRE class
WIP: moved two functions to class methods
Renamed two arrays to private names
WIP: moved coincidences process_events to analysis class
WIP: moved store_coincidences to analysis class
WIP: sciencepark/master.py: station_offsets now works
Refactored coincidence searching code

Pieces of code from sciencepark/master.py have been moved into
sapphire.analysis.coincidences.  Still a bit rough, but it works better.

TODO: refactor the analysis.coincidences code, and make it work without
traces.