AbstractBuilderTest and test support

[adrian.brock]

There's a number of projects (at least in the Microcontainer)
that have copies of the JBossXB test support classes.

Wouldn't it be a good idea to provide this support inside jbossxb.jar
like we do for the MicrocontainerTest?

Failing that, we could create a seperate archive with these classes in it.

[aloubyansky]

I think it would be better to add them to the jbossxb.jar