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/qt/rpcconsole.cpp

@@ -181,11 +181,7 @@ void RPCExecutor::request(const QString &command)
 
         emit reply(RPCConsole::CMD_REPLY, QString::fromStdString(strPrint));
     }
-<<<<<<< HEAD
-    catch (const json_spirit::Object& objError)
-=======
     catch (UniValue& objError)
->>>>>>> Convert tree to using univalue. Eliminate all json_spirit uses.
     {
         try // Nice formatting for standard-format error
         {