Move CScriptID to script.{h/cpp}

CScriptID should be next to CScript just as CKeyID is next to CPubKey

src/script/script.cpp

@@ -5,10 +5,13 @@
 
 #include <script/script.h>
 
+#include <hash.h>
 #include <util/strencodings.h>
 
 #include <string>
 
+CScriptID::CScriptID(const CScript& in) : BaseHash(Hash160(in)) {}
+
 std::string GetOpName(opcodetype opcode)
 {
     switch (opcode)