fixed bug in QR decomposition
fixed bug in QR decomposition

outer loop is over columns not rows

yangf4/core,yangf4/core,YetAnotherMinion/core,yangf4/core,YetAnotherMinion/core,YetAnotherMinion/core,YetAnotherMinion/core,YetAnotherMinion/core,yangf4/core,yangf4/core