update version number
option for scaling the display
scale size of data sent by screen client
pass screen scale to screen_client from gpu
pass screen scale from options to gpu
Optionally upscale emulator screen.

Scaling ratio must be an intger between 1 and 4. 1 being the default size.
4 is the upper limit since increasing the ratio drastically slows down
the emulator and I want to avoid unnecessary speed hits.

Closes #5