Make model configureable

[gramster]

First of all, thanks for making this; it's awesome, especially the resumability.

I am personally interested in upscaling my family videos shot on crappy video cameras back in the 90s (so mostly 480i, although in most cases I deinterlaced them when converting to digital). It would be great to be able to set the model from the command line; it seems the utility you use to do the upscaling can support 4 different options, and I'd prefer to use a non-anime one. A deinterlace option would be great too; I am guessing ffmpeg can do that when generating the frames.

I did create a fork, and added code for the different models, which may be usable (although its untested as yet, and I am not a Rust programmer; this was my first time reading and then trying to write Rust).