I wanted to see how much work remains to enable iterm2 image
display; one of the blockers was a limit in the size of the
buffer in the vte crate, which has been removed in my fork
of vte.
As part of testing our ability to absorb that data, I found
a couple of issues with applying the image cells to the display,
so this commit also takes care of that.
We still don't have code to connect the cell image data to the
opengl render layer.
