Use unordered_map for CCoinsViewCache with salted hash

src/uint256.h

@@ -21,7 +21,7 @@ public:
 template<unsigned int BITS>
 class base_uint
 {
-private:
+protected:
     enum { WIDTH=BITS/32 };
     uint32_t pn[WIDTH];
 public:
@@ -322,6 +322,8 @@ public:
     // implementation accident.
     uint256& SetCompact(uint32_t nCompact, bool *pfNegative = NULL, bool *pfOverflow = NULL);
     uint32_t GetCompact(bool fNegative = false) const;
+
+    uint64_t GetHash(const uint256& salt) const;
 };
 
 #endif