Mounting Blocks for Zonestar P802Q

Mounting blocks to attach the M8 threaded rods of the Zonestar P802Q Prusa i3 to a wooden board for more stability. I also used this blocks to correct a slightly perpendicularity error of XY (just 1.2 mm at 220 mm length).

Variations to original:
- two cable ties
- completely redesigned for Zonestar P802Q, which has an other height between the M8 rods and the ground.