Motorized flipping mirror mount

This is a motorized kinematic mirror mount, for moving mirror in/out of optical path.
The mount is for [stepper motor](https://www.sparkfun.com/products/9238) (size Nema17), shaft adapter for Thorlabs kinematic mirror mount [KM100](https://www.thorlabs.de/thorproduct.cfm?partnumber=KM100#ad-image-0).

There are two endstops at both ends of travel, made from standard 6x6 mm Arduino [pushbuttons](https://www.adafruit.com/product/367). They are mounted on top of posts, which are printed separately and connected to main frame with M3 screws.

The shaft adapter and the endstop posts have holes for M3 screws - they need gentle threading with M3 tap.

The whole thing can be bolted to Thorlabs [BA2/M](https://www.thorlabs.de/thorproduct.cfm?partnumber=BA2/M) plate for post mounting.

Motor control and tracking of endstop status was done with [RAMPS 1.4](http://reprap.org/wiki/RAMPS_1.4) shield, Arduino Mega board, and a [branch](https://github.com/nvladimus/Marlin/tree/MicroscopyStage