[ndnSIM] More intrusive changes removing use of boost::asio::io_service

Use of either removed or replaced with defunct DummyIoService for API
compatibility.

Change-Id: I9f99a944bf5cd082180e3f0ebccf977d5bf73f26
diff --git a/src/util/scheduler.cpp b/src/util/scheduler.cpp
index 513348f..431375a 100644
--- a/src/util/scheduler.cpp
+++ b/src/util/scheduler.cpp
@@ -46,7 +46,7 @@
 namespace util {
 namespace scheduler {
 
-Scheduler::Scheduler(boost::asio::io_service& ioService)
+Scheduler::Scheduler(DummyIoService& ioService)
   : m_scheduledEvent(m_events.end())
 {
 }