Relaxed umeyama test. Problem was ill-posed if linear part was scaled with very small number. This should fix bug 744.
(transplanted from 50e33ba0fb65259b5d3fef3fe4f62ae7c9941a74)

--HG--
branch : 3.2
extra : transplant_source : P%E3%3B%A0%FBe%25%9B%5D%3F%EF%3F%E4%F6%2A%E7%C9%94%1At