This is an effort to improve general performance at song select. At
least on the metal renderer, I can notice very high draw frame overheads
related to texture uploads.
By reducing the size of the texture uploads to roughly match what is
actually being displayed on screen (using a relatively inexpensive crop
operation), we can bastly reduce stuttering both during initial load and
carousel scroll.
You might ask if it's safe to disable mipmapping, but I've tested with
lower resolutions and bilinear filtering seems to handle just fine.
Bilinear without mipmaps only falls apart when you scale below 50% and
we're not going too far past that at minimum game scale, if at all.
