build: various cleanups

This commit also updates waf to version 2.0.14

Change-Id: I9334f10451589e8141583f85e6cefcf199f68490
diff --git a/wscript b/wscript
index dbf25a1..54f23ea 100644
--- a/wscript
+++ b/wscript
@@ -54,7 +54,7 @@
         VERSION_BUILD=VERSION)
 
     bld.objects(target='core-objects',
-                source=bld.path.ant_glob(['core/*.cpp']) + ['core/version.cpp'],
+                source=bld.path.ant_glob('core/*.cpp') + ['core/version.cpp'],
                 use='NDN_CXX BOOST',
                 includes='.',
                 export_includes='.')