PlotClock Expo Mod

This is a mod of the Plotclock by Joo, I created a new eraser holder and modified the marker arm to allow Expo Fine Tip pens to be used. I also did a little mod'ing on the Ariduno code so that you can send the current time in HHMMSS\n to update the time. My goal with this is to eventually use an Udoo booted with Linux / WiFi to keep accurate time.