#267 batch-cascade-delete

[Alexey Loubyansky]

Relationship roles (ejb-relationship-role) which have
<cascade-delete/> specified in ejb-jar.xml can also
have <batch-cascade-delete/> in jbosscmp-jdbc.xml.
In batch cascade-delete mode, related instances will be
removed with one SQL statement of the following form

DELETE FROM <related-table> WHERE <foreign-key> = ?

instead of specification compliant one DELETE statement
for each related instance.