Arc Reactor MK1 Stand

This is a stand for the movie accurate [Arc Reactor designed by zMark](http://www.thingiverse.com/thing:2036876), inspired by the [stand designed by Matt_Black_90](http://www.thingiverse.com/thing:548146).

This base has the following features:
- It has a 4 mm groove on the top to accomodate a square plexiglass cover. The base is strengthened to able the hold the weight of the cover.
- It has a 9 × 14.5 mm hole in the back to host a switch. You can customize the `Base.scad` file if your swit