MySql

Put mysql driver to you server configuration lib directory
for example runawfe/server/default/lib

Create MySQL Data Source in JBOSS
It should look like this
<?xml version="1.0" encoding="UTF-8"?>
<datasources>
  <local-tx-datasource>
    <jndi-name>af/ds/mysql</jndi-name>
    <connection-url>jdbc:mysql://YourIp:3306/DEMO_WF_DB?useUnicode=true&amp;characterEncoding=UTF-8</connection-url>
    <driver-class>com.mysql.jdbc.Driver</driver-class>
    <user-name>yourusername</user-name>
    <password>secret</password>
  </local-tx-datasource>
</datasources>

../hibernate_build.properties
# Hibernate configuration
hibernate.connection.datasource=java:/af/ds/mysql
hibernate.dialect=net.sf.hibernate.dialect.MySQLDialect
hibernate.transaction.factory_class=net.sf.hibernate.transaction.JTATransactionFactory
hibernate.transaction.manager.lookup=net.sf.hibernate.transaction.JBossTransactionManagerLookup
hibernate.cache_provider=net.sf.hibernate.cache.EhCacheProvider
hibernate.cache.use_query_cache=true
hibernate.show_sql=true
hibernate.jdbc.batch_size=20
hibernate.jdbc.fetch_size=20

../resources/wf/wf_jbpm.properties
jbpm.log.stdout=off
jbpm.create.tables=force-create
hibernate.connection.datasource=java:/af/ds/mysql
hibernate.dialect=net.sf.hibernate.dialect.MySQLDialect
hibernate.transaction.factory_class=net.sf.hibernate.transaction.JTATransactionFactory
hibernate.transaction.manager_lookup_class=net.sf.hibernate.transaction.JBossTransactionManagerLookup
hibernate.cache_provider=net.sf.hibernate.cache.EhCacheProvider
hibernate.cache.use_query_cache=true
hibernate.jdbc.batch_size=20
hibernate.jdbc.fetch_size=20
hibernate.show_sql=false

recompile and redeploy the system

Best regards,
Vitaliy

And don't you need the .script file like the localDB.script under ...server\default\data\hipersonic\ ?