build: make precompiled headers more useful

This can reduce the compilation time of a release
build (without tests) by more than 40%

Refs: #5212
Change-Id: I977aff0c0c7becbfee8a8b55605b81d0c014829b
diff --git a/wscript b/wscript
index 647347d..2ddc5a5 100644
--- a/wscript
+++ b/wscript
@@ -155,12 +155,10 @@
 
     bld.objects(
         target='core-objects',
-        features='pch',
         source=bld.path.find_node('core').ant_glob('*.cpp') + ['core/version.cpp'],
         use='version.cpp version.hpp NDN_CXX BOOST LIBRT',
         includes='.',
-        export_includes='.',
-        headers='core/common.hpp')
+        export_includes='.')
 
     nfd_objects = bld.objects(
         target='daemon-objects',
@@ -170,6 +168,8 @@
                                        'daemon/face/unix*.cpp',
                                        'daemon/face/websocket*.cpp',
                                        'daemon/main.cpp']),
+        features='pch',
+        headers='daemon/nfd-pch.hpp',
         use='core-objects',
         includes='daemon',
         export_includes='daemon')