Standard least squares, min || Ax - b ||_2

Modules
	gels: least squares using QR/LQ
	gelst: least squares using QR/LQ with T matrix
	gelss: least squares using SVD, QR iteration
	gelsd: least squares using SVD, divide and conquer
	gelsy: least squares using complete orthogonal factor
	getsls: least squares using tall-skinny QR/LQ

Detailed Description