JPT's Endstop-Rails for MendelMax

A set of endstop holders that use a rail system so they are easily adjustable.
State:
Y-Rail: finished.
X-Rail: in progress. should work for prusa based printers as well, when published ;)
2014-07-01 - Updated Arm:
- fixed a bug with screw hole positioning
- added an (optional) support between arm and rail
2014-07-02 - Updated Arm:
- fixed a bug with the support
- and added another support