Touchscreen tester

[Dan Stahlke]

There was a request that I open-source the touchscreen tester that I brought in last time.  Here it is:

https://github.com/dstahlke/touchscreen_tester

I'll (try to remember to) bring in a couple blank boards in case someone wants to build one.  And there is a box of these displays on the exchange table, but these are the rejects that were out of tolerance.  There are various problems, for example many were non-linear such that after calibrating on the four corners they were not accurate in the middle.  If people take all them, I'll bring in 50 more.