complete shot-in-the-dark to fix tinderbox build

tinderbox 50 is failing, trying to fix it

Change-Id: I81e3cbdb224110af3036f5726228fd88aba32748
convert GlobalImageList to SimpleReferenceObject

instead of hand-rolling it's own reference counting

Change-Id: Ie90cdce49b9dab68f1bdf487b0f308e03464f893