Tyre Gauge Bed Leveler - remix

This is a remix of JWag's (thing:1274667) version of cgcrute's Tyre Gauge Bed Leveler (thing: 918738). The changes I made were to allow the leveler to work on both my Fabrikator and Printrbot Original 3-D printers. The changes were: adding a third hook, making two of the clips that hold the gauge a little more PLA friendly, and thinning the bases of both parts from ~3.5 to 2 mm (i.e., reduce print time). I also removed the screw holes because I found JWag's method of just gluing the two parts to