first implementation of an simple atx power supply model
added cylinder segment which is defined by an angle and the standard cylinder r and h
added some additional funktions circle radius from three points, circal area and also standardized some funktionnames.
made some improvements and added tests
added OS (overSize) which is the same as epsilon
changed the parameter names to the standard (height -> h)...
added missing license
Merge pull request #5 from kr2/master

Capture MCAD work by kr2