API for supports and licences for Scrooge

also: I hope fixing the date will fix the randomly appearing error in tests
 """
Returns only items that have a timespan (marked by begin_field and
end_field) that contains given date
"""
or
 """Returns only items that have a timespan (marked by begin_field and
end_field) that contains given date"""

but plx, no

"""
Returns only items that have a timespan (marked by begin_field and
end_field) that contains given date"""