PgManager: add support for str, repr of RowDict.
--- a/pgtoolkit/pgmanager.py	Tue Mar 19 16:46:36 2013 +0100
+++ b/pgtoolkit/pgmanager.py	Thu Mar 21 17:40:11 2013 +0100
@@ -148,6 +148,9 @@
     def items(self):
         return self._dict.items()
 
+    def __repr__(self):
+        return 'RowDict(%s)' % str(self._dict.items())
+
 
 class Cursor(psycopg2.extensions.cursor):