#177 relative ejb links now work...once

[David Jencks]

I implemented relative ejb-links for jboss 3. These are

<ejb-link>../product/product.jar#MyEJB</ejb-link>

where the ear looks like

acct/acct.jar (has link in ejb-jar.xml)
product/product.jar (has MyEJB)

The EjbLinkUnitTestCase passes when run once by itself
on a newly started server.

However, it can't be run twice at the moment due to
ClassCast problems. I added
InternalNamingClassReplacementUnitTestCase to make this
problem even more obvious.