MSP: Generate random factors for each place
MSP: Pass a PathPtr to Strategy instead of the weights

This is in preparation to storing domination status within a path in
order to be able to explicitly mark a task / a path as dead / dominated.
MSP: Add atomic domination to Path
MSP: Explicitly handle added and removed paths in set

Altered SetMapper's signature to explicitly return added and removed
paths. Added paths are handled as before, while removed paths are marked
as dominated.
MSP: Rename SetMapper -> Sets
MSP: Add added and removed paths to Set signatures