chainparams: move CCheckpointData into chainparams.h

This unties CChainParams from its dependency on checkpoints. Instead, now it
only depends on the raw checkpoint data.

src/chainparams.h

@@ -7,7 +7,6 @@
 #define BITCOIN_CHAINPARAMS_H
 
 #include "chainparamsbase.h"
-#include "checkpoints.h"
 #include "consensus/params.h"
 #include "primitives/block.h"
 #include "protocol.h"
@@ -24,6 +23,14 @@ struct SeedSpec6 {
     uint16_t port;
 };
 
+typedef std::map<int, uint256> MapCheckpoints;
+
+struct CCheckpointData {
+    MapCheckpoints mapCheckpoints;
+    int64_t nTimeLastCheckpoint;
+    int64_t nTransactionsLastCheckpoint;
+    double fTransactionsPerDay;
+};
 
 /**
  * CChainParams defines various tweakable parameters of a given instance of the
@@ -67,7 +74,7 @@ public:
     const std::vector<CDNSSeedData>& DNSSeeds() const { return vSeeds; }
     const std::vector<unsigned char>& Base58Prefix(Base58Type type) const { return base58Prefixes[type]; }
     const std::vector<SeedSpec6>& FixedSeeds() const { return vFixedSeeds; }
-    const Checkpoints::CCheckpointData& Checkpoints() const { return checkpointData; }
+    const CCheckpointData& Checkpoints() const { return checkpointData; }
 protected:
     CChainParams() {}
 
@@ -87,7 +94,7 @@ protected:
     bool fRequireStandard;
     bool fMineBlocksOnDemand;
     bool fTestnetToBeDeprecatedFieldRPC;
-    Checkpoints::CCheckpointData checkpointData;
+    CCheckpointData checkpointData;
 };
 
 /**