Remove now-unused methods from arith_uint256 and base_uint

- Methods that access the guts of arith_uint256 are removed,
as these are incompatible between endians. Use uint256 instead

- Serialization is no longer needed as arith_uint256's are never
read or written

- GetHash is never used on arith_uint256

src/arith_uint256.h

@@ -232,26 +232,6 @@ public:
     void SetHex(const std::string& str);
     std::string ToString() const;
 
-    unsigned char* begin()
-    {
-        return (unsigned char*)&pn[0];
-    }
-
-    unsigned char* end()
-    {
-        return (unsigned char*)&pn[WIDTH];
-    }
-
-    const unsigned char* begin() const
-    {
-        return (unsigned char*)&pn[0];
-    }
-
-    const unsigned char* end() const
-    {
-        return (unsigned char*)&pn[WIDTH];
-    }
-
     unsigned int size() const
     {
         return sizeof(pn);
@@ -268,40 +248,6 @@ public:
         assert(WIDTH >= 2);
         return pn[0] | (uint64_t)pn[1] << 32;
     }
-
-    unsigned int GetSerializeSize(int nType, int nVersion) const
-    {
-        return sizeof(pn);
-    }
-
-    template<typename Stream>
-    void Serialize(Stream& s, int nType, int nVersion) const
-    {
-        s.write((char*)pn, sizeof(pn));
-    }
-
-    template<typename Stream>
-    void Unserialize(Stream& s, int nType, int nVersion)
-    {
-        s.read((char*)pn, sizeof(pn));
-    }
-
-    // Temporary for migration to blob160/256
-    uint64_t GetCheapHash() const
-    {
-        return GetLow64();
-    }
-    void SetNull()
-    {
-        memset(pn, 0, sizeof(pn));
-    }
-    bool IsNull() const
-    {
-        for (int i = 0; i < WIDTH; i++)
-            if (pn[i] != 0)
-                return false;
-        return true;
-    }
 };
 
 /** 256-bit unsigned big integer. */
@@ -336,8 +282,6 @@ public:
     arith_uint256& SetCompact(uint32_t nCompact, bool *pfNegative = NULL, bool *pfOverflow = NULL);
     uint32_t GetCompact(bool fNegative = false) const;
 
-    uint64_t GetHash(const arith_uint256& salt) const;
-
     friend uint256 ArithToUint256(const arith_uint256 &);
     friend arith_uint256 UintToArith256(const uint256 &);
 };