Prusa i3 MK2: 3 Point Y Motor Holder enforced

This is a remake of this thing: https://www.thingiverse.com/thing:1837853 - thanks to MartinMajewski. It allows using NEMA shock absorber on the Y-axis of the Prusa I3 MK2 and is additionally significantly stronger on the holding rods.

I got my dampers from here: http://www.ebay.de/itm/Shock-Absorber-Stepper-Vibration-Damper-for-Nema17-Stepper-Motor-/172311965775