Support arrays of references (and named clusters w/o front panel items)

[maherhome]

We have a "group" of occurrences.  We can't identity individual occurrencs easily because you can't store them in an array (where we would use indexes to identify).  When using a cluster they all get the same name (labels aren't used!) which is bug-prone.  The only workaround is to create a control cluster, and that's not a clean solution.

[JCC_(SK)]

Constants Reference Array of fix size should be supported.

[crossrulz]

You don't really need to make the reference cluster a control.  It can be a constant.  You just have to change the labels.