Use unsigned int for callCount and costs to avoid integer overflow

[Echron]

(Tested with XDebug3 profiler file)
I replaced all cost and call count integers with unsigned int (0 to 4,294,967,295). If this is not enough, we can change this to 'unsigned long long' (0 to 18,446,744,073,709,551,615).
https://docs.microsoft.com/en-us/cpp/cpp/data-type-ranges?view=msvc-170

[danielbeardsley]

I think we'll want long long because #132 indicates the new format deals in 10 nanoseconds which could easily get past 32 bit range (40 seconds).