Add ignore for Base classes from Doctrine and Propel ORM.

Symfony.gitignore

@@ -4,3 +4,8 @@ web/uploads/*
 config/databases.yml
 config/propel.ini
 data/sql
+lib/filter/doctrine/base/Base*
+lib/form/doctrine/base/Base*
+lib/model/doctrine/base/Base*
+lib/model/om/*
+lib/model/map/*