Add GDEY037T03 e-paper driver

[jplexer]

In my spare time I've been working on writing custom firmware for a commercial bedside clock by reversing the circuit. The only driver missing was for the Display (GDEWY037T03) and I thought if I wrote it anyway might as well upstream it :)

[phoddie]

Super cool.

It looks perfect.

I only had time for a quick read this afternoon. A couple of notes:

• Freezing the prototype is unnecessary as xsl (the XS linker) takes care of that. It didn't always, which is why there's still some SDK code doing it.
• The only performance bottleneck appears to be #toNative(), but it probably doesn't matter for low-frequency display updates. The cycle counter in me would process 8 pixels at a time in the inner loop to reduce the calculations to write to the output buffer.

...writing custom firmware for a commercial bedside clock...

This does lead to a couple of natural questions... what's the product, and how can I try this? ;)