MP Select Mini 8mm Gantry Support and Logitech C525 Mount

This is a multi-project remix/mashup for the MP Select Mini.

Foremost, it is a remix of [svideo](http://www.thingiverse.com/svideo/)'s [X Gantry Support + Camera Mount](http://www.thingiverse.com/thing:1864625) which adds support for an 8mm rod and bearings. If that's what you're after, you can just grab "base" and "bracket" and be good to go! Note that I while I simply enlarged the rod opening on the base, I did entirely rebuild the bracket to add the following niceties:
- Larger zip-tie h