move pow constants to chainparams

src/chainparams.h

@@ -70,6 +70,9 @@ public:
     bool AllowMinDifficultyBlocks() const { return fAllowMinDifficultyBlocks; }
     /* Make standard checks */
     bool RequireStandard() const { return fRequireStandard; }
+    int64_t TargetTimespan() const { return nTargetTimespan; }
+    int64_t TargetSpacing() const { return nTargetSpacing; }
+    int64_t Interval() const { return nTargetTimespan / nTargetSpacing; }
     const std::string& DataDir() const { return strDataDir; }
     /* Make miner stop after a block is found. In RPC, don't return
      * until nGenProcLimit blocks are generated */
@@ -95,6 +98,8 @@ protected:
     int nEnforceBlockUpgradeMajority;
     int nRejectBlockOutdatedMajority;
     int nToCheckBlockUpgradeMajority;
+    int64_t nTargetTimespan;
+    int64_t nTargetSpacing;
     std::string strDataDir;
     int nMinerThreads;
     std::vector<CDNSSeedData> vSeeds;