Adjustments for the 'Flag' app.
OIT: fix for 'out of memory' crash on Mali GPUs.
~The thing still does not fully work there - there are still strange flashes in apps that innvolve OIT, for example in 'Triblur'.
OIT: correction for blending in Pass4
OIT: move towards 4 passes ( clear - build - collapse - render )
OIT: correct depth
OIT: lots of progress on all fronts. Still a few bugs to solve though!