render_fs_speed_10183 (rebased onto develop)



This is the same as gh-616 but rebased onto develop.

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Simple page in /webtest/ to look at performance for rendering every plane in an Image.

Once this is in dev_4_4 and develop, we can use it to compare speed of rendering in FS.

To test: go to /webtest/render_performance/<imageId>/ and click button. Refresh to repeat.