build: move `config.hpp` private header to `detail` subdir

Change-Id: I9f3bb2e288450f002ecec77b52411647ed4fea5a
diff --git a/src/common.hpp b/src/common.hpp
index 4232aa0..629463b 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -20,7 +20,7 @@
 #ifndef NDN_NAC_COMMON_HPP
 #define NDN_NAC_COMMON_HPP
 
-#include "config.hpp"
+#include "detail/config.hpp"
 
 #ifdef NAC_WITH_TESTS
 #define NAC_VIRTUAL_WITH_TESTS virtual
diff --git a/tests/wscript b/tests/wscript
index 42d537d..b983992 100644
--- a/tests/wscript
+++ b/tests/wscript
@@ -8,4 +8,5 @@
         name='unit-tests',
         source=bld.path.ant_glob('**/*.cpp'),
         use='BOOST_TESTS libndn-nac',
+        includes=top,
         install_path=None)
diff --git a/wscript b/wscript
index 833277c..76bbe22 100644
--- a/wscript
+++ b/wscript
@@ -67,7 +67,7 @@
     # or conf.define_cond().  Everything that was added directly to conf.env.DEFINES
     # will not appear in the config header, but will instead be passed directly to the
     # compiler on the command line.
-    conf.write_config_header('config.hpp', define_prefix='NAC_')
+    conf.write_config_header('src/detail/config.hpp', define_prefix='NAC_')
 
 def build(bld):
     version(bld)
@@ -93,8 +93,8 @@
         cnum=VERSION_BASE,
         source=bld.path.ant_glob('src/**/*.cpp'),
         use='BOOST NDN_CXX',
-        includes=['src', '.'],
-        export_includes=['src', '.'])
+        includes='src',
+        export_includes='src')
 
     if bld.env.WITH_TESTS:
         bld.recurse('tests')
@@ -107,7 +107,7 @@
 
     # Install header files
     bld.install_files('${INCLUDEDIR}/ndn-nac', bld.path.find_dir('src').ant_glob('*.hpp'))
-    bld.install_files('${INCLUDEDIR}/ndn-nac', bld.path.find_resource('config.hpp'))
+    bld.install_files('${INCLUDEDIR}/ndn-nac/detail', 'src/detail/config.hpp')
 
     bld(features='subst',
         source='libndn-nac.pc.in',