Add comments in K-partial alternatives computation
The computation of k-partial alternatives was added in
a prior commit. This commit implements the function
`Configuration::is_compatible_with(const History&)`
which is used during the computation of K-partial alternatives
to determine which events go with which spikes.
Note: The implementation that currently exists for
K-partial alternatives is a first go at an implementation
of the algorithm. There are clear spots within the computation
where performance may be improved with some more clever ideas.
For now, we're working towards a proof-of-concept: we can
optimize more heavily later
