std::pair's to structures

I've replaced std::pair&lt;NodeID, NodeID&gt; and std::pair&lt;NodeID, bool&gt; with structs RestrictionSource and RestrictionTarget. I think now it's more readable and easier to understand.
Also replaced wrong type in CheckForEmanatingIsOnlyTurn method (in 'for' was RestrictionSource instead of RestrictionTarget).
Yes, you are right. Sorry for not being clear here. I meant that we remove the std::pair has function from Util/StdHashExtension.h and then add a (generic) hash combine function there. This header is then included in RestrictionMap.