src: Reorganizing source code in preparation to merge NRD code

Note that as of this commit, there are several changes in location of
compiled binaries in `build/` folder:

* `nfd` has been moved to `build/bin/nfd`
* `unit-tests` has been split into `unit-tests-core` and `unit-tests-daemon`

Change-Id: I2c830c117879edbaa5457d6423c13f0273285919
Refs: #1486
diff --git a/daemon/mgmt/face-manager.cpp b/daemon/mgmt/face-manager.cpp
index 7861935..79822f7 100644
--- a/daemon/mgmt/face-manager.cpp
+++ b/daemon/mgmt/face-manager.cpp
@@ -31,7 +31,7 @@
 #include "fw/face-table.hpp"
 #include "face/tcp-factory.hpp"
 #include "face/udp-factory.hpp"
-#include "mgmt/config-file.hpp"
+#include "core/config-file.hpp"
 
 #ifdef HAVE_UNIX_SOCKETS
 #include "face/unix-stream-factory.hpp"