Reverts a decision from commit 10b7cd63f5
in order to both make the Classic theme backportable to 1.12 and
eliminate an unnecessary complication for UMC.
At some point in the future, the Default theme will replace Classic when
the rumored UnitBox theme becomes the default, so I'd say naming its
directories "classic" makes sense, while the current Classic theme is
the "legacy" classic.
If we hadn't gotten stuck with Default using "classic" dirs in 1.12
there would be no need for any of this irritating nonsense.
This reverts commit 5d36e382c7.
It's been found to cause all kinds of terrain glitches on Windows and
Linux. Please do not try experimental image compression alternatives
without discussing and reviewing first.
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Total saving: 37 KiB = 7% decrease
