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/face/tcp-transport.hpp b/daemon/face/tcp-transport.hpp
index adf5085..a6a2048 100644
--- a/daemon/face/tcp-transport.hpp
+++ b/daemon/face/tcp-transport.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2018,  Regents of the University of California,
+ * Copyright (c) 2014-2019,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -27,7 +27,6 @@
 #define NFD_DAEMON_FACE_TCP_TRANSPORT_HPP
 
 #include "stream-transport.hpp"
-#include "core/scheduler.hpp"
 
 namespace nfd {
 namespace face {