use composite site of multiple versions of JBT instead of single latest site as it's more resilient to frequent builds (JBIDE-17536) >> master

builds have always been a temporary place.

I don't see why anyone would be confused about wether a nightly site is an aggregate or composite since the nightly site under updates/ exist solely for having a *stable* url to point to that will get updates when new nightly (somewhat tested) builds  are available.

But of course there could be some *techinical* reason. Do you know any for why we have an aggregate in /updates/nightly and not just a composite ?