fix #9917: adjust tile drawing for big images (rebased onto develop)

You may find that if you zoom enough you get some black tiles that are associated in the logs with Java running out of heap space. These should be unrelated to this PR: Insight does those the same with or without it.

This is the same as gh-1444 but rebased onto develop.

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Try to reproduce https://trac.openmicroscopy.org.uk/ome/ticket/9917 using OpenGL Insight. `test_images_good/cellsens/brian/_BZ cfos1-2_05_/` is a great test. Make sure that all the tiles appear in the full image viewer, at the correct aspect ratio.