Stop channeling printbuffers to stdostream. Instead, provide an invocation CHANNEL_PRINTS.

luprex/cpp/core/luaconsole.cpp

@@ -91,7 +91,7 @@ void LuaConsole::add(eng::string line) {
     // Try to parse the lua expression
     {
         LuaVar result;
-        LuaDefStack LS(lua_state_, result);
+        LuaExtStack LS(lua_state_, result);
         eng::string errmsg = LS.load(result, partial, "stdin");
         if (errmsg.empty()) {
             words_.push_back(lua_mode);