boost: moveonly: create eccryptoverify.h|cpp and move helper functions there

Eventually (after 0.10) these files will hold the logic for crypto
verification routines, and CKey/CPubKey will call into them.

src/eccryptoverify.h

@@ -0,0 +1,19 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2013 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_EC_CRYPTO_VERIFY_H
+#define BITCOIN_EC_CRYPTO_VERIFY_H
+
+#include <vector>
+#include <cstdlib>
+class uint256;
+
+namespace eccrypto {
+
+bool Check(const unsigned char *vch);
+bool CheckSignatureElement(const unsigned char *vch, int len, bool half);
+
+} // eccrypto namespace
+#endif