* This change implements certain
speed improvements on top of
upstream GxEPD2 that are not fully
accepted by the upstream maintainer.
* The change Adds a new WatchyDisplay class
and implements the mods in there.
* Using transactions for SPI communication
* Remove extra delays for yield()
* Remove 10ms active waits in resets
* This reduces (874ms -> 657ms) the display
update. Making it more responsive and
Saving 21mJ/update or 2.6mAh/day
Daniel Ansorregui