#70 Transaction Isolation is configurable

[Bill Burke]

The JDBC connection transaction isolation level is now
configurable with org.jboss.jdbc.XADataSourceLoader in
jboss.jcml

The new attribute is:
<attribute name="TransactionIsolation">iso</attribute>

Valid values are

TRANACTION_NONE
TRANSACTION_READ_COMMITTED
TRANSACTION_READ_UNCOMMITTED
TRANSACTION_REPEATABLE_READ
TRANSACTION_SERIALIZED

Please note that not all JDBC drivers support all the
above isolation levels. For instance, I believe
Oracle only supports read committed, none, and
serialized.