Remove JSON Spirit wrapper, remove JSON Spirit leftovers

- implement find_value() function for UniValue
- replace all Array/Value/Object types with UniValues, remove JSON Spirit to UniValue wrapper
- remove JSON Spirit sources

src/rpcserver.h

@@ -17,7 +17,8 @@
 #include <memory>
 
 #include <boost/function.hpp>
-#include "json_spirit_wrapper.h"
+
+#include "univalue/univalue.h"
 
 class AsyncRPCQueue;
 class CRPCCommand;