Generalised arguments to Measurement object

A measurement need not act on data in the database, so it may not need
to be given views. In this case, it makes more sense to generalize the
arguments to Measurement so that it accepts arbitrary args and kwargs.
Added meas_results != None clause to results dumping in Project

If the user wants to write their results back to the database, let them.
If they have intermediate results that they want to call new
measurements on, they could save them to the database and not dump them
into files.