build: various updates

 * Upgrade waf to 2.0.14
 * Sync default compiler flags with ndn-cxx
 * Remove unused pch waf tool
 * Simplify compilation of unit-tests

Change-Id: I2aa21454dd5d691ad2093923582443e5f8329ba7
diff --git a/tests/wscript b/tests/wscript
index facae68..65c5eeb 100644
--- a/tests/wscript
+++ b/tests/wscript
@@ -4,19 +4,8 @@
     if not bld.env['WITH_TESTS']:
         return
 
-    bld(
-        features='cxx',
-        name='unit-tests-main',
-        target='unit-tests-main',
-        source='main.cpp',
-        defines=['BOOST_TEST_MODULE=PSync Unit Tests'],
-        use='PSync'
-    )
-
-    bld.program(
-        target='../unit-tests',
-        features='cxx cxxprogram',
-        source=bld.path.ant_glob(['**/*.cpp'], excl=['main.cpp']),
-        use='PSync unit-tests-main',
-        install_path=None,
-    )
+    bld.program(target='../unit-tests',
+                name='unit-tests',
+                source=bld.path.ant_glob('**/*.cpp'),
+                use='PSync',
+                install_path=None)