Yet another Calibration part

###YACT
This is a calibration part to test if your printer prints with the right dimension.
a clearance of 0.1 is present between the two shapes.
it can be easily removed editing the [Freecad](http://www.freecadweb.org) file.
there is a spreadsheet inside with the gap value

edit 20/09 :
added a chamfer on the base limit cleaning after printing