Variable tile size

[alexharris]

From: @AryEstLa

Create ability to add "larger pixels", or "tiles" as done in RGBitsy.

[alexharris]

Another request for this from Boris:

” In my case, I would want to have an image that is for example 400px x 200px with pixel sizes of 4x4 (so one pixel/dot on the image is 4 actual pixels by 4 actual pixels), but then have the option to reduce the size of the pixel/dot on the image (so from 4x4 to perhaps 2x2 or 1x1 or whatever one would want) without changing the overall size (keeping the whole image still at 400px x 200px).“