Hardkernel Odroid XU4 3D Model

This provides the ability to show or view a representative model of the Hardkernel/Odroid XU4 ARM processor board. The primary use case for the model is the development of 3d printed cases for the XU4 board. The model generated is *not* suitable for printing.

This leverages v1.1d of the XU4 Model script originally provided by user hominoid on the Hardkernel/Odroid support forum at www.forum.odroid.com. Reference the 'XU4 Model for OpenSCAD' thread at URL https://forum.odroid.com/viewtopic.php?f=97&t=26243 for info on that origin. Odroid XU4 Model Version 2 is a major revision to that v1.1d script. Comments at the top of the openSCAD file describe the enhancements from the v1.1d origin.

The scad file is heavily commented, and a user guide for the model has been included in PDF format. The model would normally be accessed by "including" this scad file within the higher level design, and then using the odroid_xu4 module to create the model. For higher level designs to access