Allow setting image size from commandline
I would like to minimize the boilerplate setup for an image when I start grafx2, booting right into a picture with the dimensions I need. I suggest having a -size parameter that allows you to specify the picture size from the command line separately from the video mode.
I have a small patch but I haven't spent much time reading the source code, so it may be off from the preferable approach. One consideration is how to handle setting both the size and loading a picture. Ignore it silently, fail, crop image? In my patch it happens to be ignored silently as a side effect.