bzr revid: vmt@openerp.com-20110511172448-p12p1rizvf3lqv97
bzr revid: vmt@openerp.com-20110511164144-8o1bl6jfb8k7keak
- made upgrade_graph a method of Graph called add_modules - removed unnecessary create_graph function. bzr revid: vmt@openerp.com-20110511152810-etqru9pct1zwyqno