Include first day of week in Trovebox results

The Trovebox API does NOT include results for the date in takenAfter,
so we have to substract one day from that date before sending it to
the API.
Add --years option to set the numbers of years to go back

Add a command-line option to specify the number of years
clj-photo-memories should search for memories. The default is 5 so
the behaviour of current calls doesn't change.

While at it, do some small clean-ups.