Filleted parametric wade's projector ceiling mount

This is a remodeled version of Wade's projector ceiling mount, but with smaller holes (M5 with 0.3mm clearance) and filleted arms.

This includes fillet.scad from https://github.com/clothbot/ClothBotCreations/blob/master/utilities/fillet.scad, which generates very nice filleted joints.

The projector plate is redesigned for the BenQ W1070+ (a.k.a. HT1075), and is parametric so you can generate one for any projector if you figure out the XY-coordinates of the screw holes in mm.

Update: The filleted swivel piece snapped pretty easily when the arms are squeezed inwards with one hand. I'm printing another copy of both versions of the swivel piece to determine if the fillet was a good idea or not.

Update #2: Both new pieces snapped with about the same amount of force. Perhaps the base of the swivel piece needs to be expanded.

Update #3: Expanded the interface between swivel.stl and ceiling-plate.stl. This should make both stronger.

Update #4: The projector plate