core+daemon: eliminate scheduler::{schedule,cancel} wrappers

Also move core/global-io.hpp to daemon/global.hpp

Refs: #4528, #4883
Change-Id: I0b99029f1a19d7451aab57099cd3303b7eb42ff3
diff --git a/daemon/rib/service.hpp b/daemon/rib/service.hpp
index fe9b110..1c07d7e 100644
--- a/daemon/rib/service.hpp
+++ b/daemon/rib/service.hpp
@@ -111,7 +111,7 @@
 
   ndn::KeyChain& m_keyChain;
   ndn::Face m_face;
-  ndn::util::Scheduler m_scheduler;
+  Scheduler m_scheduler;
   ndn::nfd::Controller m_nfdController;
 
   Rib m_rib;