Desk Clamp v3

I saw a post in /r/FreeCAD where someone wanted to make this part 10mm taller. There was a suggestion to just edit the OpenSCAD, but the OP said they had had some trouble with that.

This file is a slight refactor of ggoss's original, with the code cleaned up a bit to make it easier to change the dimensions of the clamp. The biggest change is the addition of a clampHeight and clampDepth variables at the top of the file which can be used to change the dimensions.

I've also made it so the starting value for the height is 10mm taller than the original (which is what OP was looking for).

And just for the sake of saying it, I'm not knocking the original design in the slightest- just making it a bit easier for people to modify it.