Fix texture trim handling

[ZZZank]

• TextureInfo#trim(int,int,int,int) now actually uses provided args
• DrawableNineSliceTexture will now make use of texture trim params

for a 14 * 50 texture (expanded to 64*64) setup as:

this.scrollbarBackground = registerGuiSprite("scrollbar_background", 64, 64)
	.trim(0, 64 - 14, 0, 64 - 50)
	.slice(1, 1, 1, 1);

Before	After

• removed .trim(...) call for arrow icon texture, because this breaks arrow shadow and overall shape