Rotation of 3 points in 3D implemented and covered by tests.

Only interval and rational calculation implemented correctly.
Double arithmetic calculation implemented WRONG! (test will fail, if you will uncomment double-arithmetic optimisation) It seems, that I was wrong in eps calcultaion. My calculations - https://www.dropbox.com/s/6ntftgxuld53clz/19_3.jpeg?dl=0
But orientation of 3D points is usable - but it can be a bit slow (interval and rational arithmetic driven).
Балбес я.