Clean graphviz parser build a little bit. Include parser files generated

by corresponding bison invocation.

Patch from anonymous user.


[SVN r21949]

libs/graph

@@ -1 +1 @@
-Subproject commit 9e39cceb5a9c92c5a34cac44c263f598d0ee8fb5
+Subproject commit df87cf35fc3078d352daeb992ebb9c3828476098