r10293 - Theme support button size

[Andarix]

The size 40 pixel not work.



40 is a multiple of 8. So I'm surprised that this size doesn't work. 42 works, however.

[prissi]

The zoom routine used the same scaling steps as for the display 2:1, 3.2, 4:3, 1:1, 3:4, 5:8, 1:8, 3:8, 1:4, 1:8

With 32 pixel this gives the possbile sizes of 64, 48, 42 (actually 42.6667, but it will be trucated to 42), 32 (and smaller like 24 ...).