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/table/cs-policy-priority-fifo.cpp b/daemon/table/cs-policy-priority-fifo.cpp
index 7984739..f350c72 100644
--- a/daemon/table/cs-policy-priority-fifo.cpp
+++ b/daemon/table/cs-policy-priority-fifo.cpp
@@ -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,
@@ -25,6 +25,7 @@
 
 #include "cs-policy-priority-fifo.hpp"
 #include "cs.hpp"
+#include "daemon/global.hpp"
 
 namespace nfd {
 namespace cs {
@@ -117,8 +118,8 @@
   }
   else {
     entryInfo->queueType = QUEUE_FIFO;
-    entryInfo->moveStaleEventId = scheduler::schedule(i->getData().getFreshnessPeriod(),
-                                                      [=] { moveToStaleQueue(i); });
+    entryInfo->moveStaleEventId = getScheduler().schedule(i->getData().getFreshnessPeriod(),
+                                                          [=] { moveToStaleQueue(i); });
   }
 
   Queue& queue = m_queues[entryInfo->queueType];
@@ -133,7 +134,7 @@
 
   EntryInfo* entryInfo = m_entryInfoMap[i];
   if (entryInfo->queueType == QUEUE_FIFO) {
-    scheduler::cancel(entryInfo->moveStaleEventId);
+    entryInfo->moveStaleEventId.cancel();
   }
 
   m_queues[entryInfo->queueType].erase(entryInfo->queueIt);