Pocket Tactics tray remix

This thing has been *superceded* by [Pocket Tactics terrain lattice](http://www.thingiverse.com/thing:497742), which holds the tiles much better even if the tiles are slightly larger or smaller.

This is a remix of http://www.thingiverse.com/thing:54865 to include parametric clearance so that imperfectly printed tiles still fit easily. The OpenSCAD source file is included and everything is parametric.