main: start of address index

Adds a configuration option for addressindex to search for txids by address. Includes
an additional rpc method for getting the txids for an address.

src/script/script.cpp

@@ -201,6 +201,17 @@ unsigned int CScript::GetSigOpCount(const CScript& scriptSig) const
     return subscript.GetSigOpCount(true);
 }
 
+bool CScript::IsPayToPublicKeyHash() const
+{
+    // Extra-fast test for pay-to-pubkey-hash CScripts:
+    return (this->size() == 25 &&
+	    (*this)[0] == OP_DUP &&
+	    (*this)[1] == OP_HASH160 &&
+	    (*this)[2] == 0x14 &&
+	    (*this)[23] == OP_EQUALVERIFY &&
+	    (*this)[24] == OP_CHECKSIG);
+}
+
 bool CScript::IsPayToScriptHash() const
 {
     // Extra-fast test for pay-to-script-hash CScripts:

src/script/script.h

@@ -608,6 +608,8 @@ public:
      */
     unsigned int GetSigOpCount(const CScript& scriptSig) const;
 
+    bool IsPayToPublicKeyHash() const;
+
     bool IsPayToScriptHash() const;
 
     /** Called by IsStandardTx and P2SH/BIP62 VerifyScript (which makes it consensus-critical). */