configurable sarrus linkage

has these options for configuration.

//controls the sarrus linkage height and width
linkageheight=80;
linkagewidth=50;

//hole radious in mm
holewidth=4;
outerhole=10;
//Height of the tear triangle
tearangle=90;

linkageholeangle=90;
baseholeangle=0;

Please not that this is still fairly early. I haven't added many features. The idea is that you put a screw through the hole and separate the joint with 2mm washers. Hopefully this will put the transverse motion within tolerance needed to build a Cartesian robot.