Make use of logger provided by ndn-cxx

This commit also introduces a basic implmentation of DummyForwarder to
remove dependency on (and uncertainty of) the running instance of NFD.

Change-Id: Iba9fcbf3d3ebb1a5ae47018ad3be5d7d2b9c7462
diff --git a/src/db-helper.cpp b/src/db-helper.cpp
index 0597c12..2096138 100644
--- a/src/db-helper.cpp
+++ b/src/db-helper.cpp
@@ -26,7 +26,7 @@
 namespace ndn {
 namespace chronoshare {
 
-INIT_LOGGER("DbHelper")
+_LOG_INIT(DbHelper);
 
 namespace fs = boost::filesystem;