Add pgen.stamp to svn:ignore and friends
diff --git a/.hgignore b/.hgignore
index 12f288c..ed3d9f7 100644
--- a/.hgignore
+++ b/.hgignore
@@ -30,6 +30,7 @@
 Modules/Setup.local
 Modules/config.c
 Parser/pgen$
+Parser/pgen.stamp$
 ^core
 ^python-gdb.py
 ^pybuilddir.txt