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/table/fib-entry.hpp b/daemon/table/fib-entry.hpp
index e30f9d7..1d03426 100644
--- a/daemon/table/fib-entry.hpp
+++ b/daemon/table/fib-entry.hpp
@@ -22,8 +22,8 @@
  * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
  **/
 
-#ifndef NFD_TABLE_FIB_ENTRY_HPP
-#define NFD_TABLE_FIB_ENTRY_HPP
+#ifndef NFD_DAEMON_TABLE_FIB_ENTRY_HPP
+#define NFD_DAEMON_TABLE_FIB_ENTRY_HPP
 
 #include "fib-nexthop.hpp"
 
@@ -111,4 +111,4 @@
 } // namespace fib
 } // namespace nfd
 
-#endif // NFD_TABLE_FIB_ENTRY_HPP
+#endif // NFD_DAEMON_TABLE_FIB_ENTRY_HPP