remove ant dependency from AS7 (JPA)

Currently, org.hibernate.tool.hbm2ddl.SchemaExportTask is deprecated but still included with Hibernate core (4.0.0.Final). SchemaExportTask depends on ant. We should be able to remove the ant dependency from AS7.1. If someone wants to run ANT tasks, they can get the ANT jars elsewhere. If someone wants to include ANT with AS7, it shouldn't be because of SchemaExportTask (since AS7 doesn't depend on the SchemaExportTask class).