Add ability to configure "distinctname" for EJB deployments

The EJB client API allows for selecting EJBs based on a combination of appname, modulename, distinctname and beanname. Currently all deployments default to a empty distinct name. We should allow a way to configure distinct names to these deployments.

I'm marking this for 7.1.0.Final for now, since I don't think it's a hard requirement for 7.1.0.CR1. But if anyone feels it's required for CR1 then please mark accordingly.