old:
<property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect"/>
change to:
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
consider to change it in both files. then it should work :)
it´s a failure in the jbpm documentation. i also wrote the jbpm-guys an e-mail about that but obviously they haven´t updated it yet