summary: Adjust to the newly-public DEFAULT_CONFIG

This keeps us up to date with the core commit e9dc1dd (settings: Make
DEFAULT_CONFIG public, 2013-03-24).

summary/summary.py

@@ -11,11 +11,11 @@ import types
 from pelican import signals
 
 def initialized(pelican):
-    from pelican.settings import _DEFAULT_CONFIG
-    _DEFAULT_CONFIG.setdefault('SUMMARY_BEGIN_MARKER',
-                               '<!-- PELICAN_BEGIN_SUMMARY -->')
-    _DEFAULT_CONFIG.setdefault('SUMMARY_END_MARKER',
-                               '<!-- PELICAN_END_SUMMARY -->')
+    from pelican.settings import DEFAULT_CONFIG
+    DEFAULT_CONFIG.setdefault('SUMMARY_BEGIN_MARKER',
+                              '<!-- PELICAN_BEGIN_SUMMARY -->')
+    DEFAULT_CONFIG.setdefault('SUMMARY_END_MARKER',
+                              '<!-- PELICAN_END_SUMMARY -->')
     if pelican:
         pelican.settings.setdefault('SUMMARY_BEGIN_MARKER',
                                     '<!-- PELICAN_BEGIN_SUMMARY -->')