Parallel holder for LMS thin parallel set (#3946)

Remix to hold the set of 9 parallels from Little Machine Shop. Holder for the parallel shims forthcoming.

Holds 9 pairs of 3" thin (0.125" thick each) parallels.

Nice design, printed quickly ~2 hours. I got some fat inner corners, so the parallels are held very tightly. I'm going to clean up the corners with a razor blade for a looser fit.

Thanks to nady_ice for the design, and cheers!