UP-4305 : Add parameter target so we can have specific portlets launc...

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I have no objection to one or many JIRA issues backlogging refactoring `RDBMDistributedLayoutStore`.  I'd even be favor of backlogging a "Refactor away from using inner classes anywhere in uPortal because it turns out they're just a bad idea." JIRA.  But I'm not terribly hopeful that backlogging that sort of thing is going to help a lot -- I think what's really going to help is writing a new layout manager that's a cleaner implementation, and then `RDBMDistributedLayoutStore` just goes away along with a bunch of other troubled code.