SetMockTime() for cleaner unit testing

src/util.h

@@ -199,6 +199,7 @@ void ShrinkDebugFile();
 int GetRandInt(int nMax);
 uint64 GetRand(uint64 nMax);
 int64 GetTime();
+void SetMockTime(int64 nMockTimeIn);
 int64 GetAdjustedTime();
 void AddTimeData(unsigned int ip, int64 nTime);
 std::string FormatFullVersion();