longer provide access to their underlying image (they actually still do,
but not in the normal course of affairs). This will allow us to use
"trimmed" tiles which are trimmed to the smallest rectangle that contains
the non-transparent pixels in a tile image, which will shrink up our
components and other tiles a great deal.
git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@1339 542714f4-19e9-0310-aa3c-eee0fc999fb1
Michael Bayne