Scalar operations

Collaboration diagram for Scalar operations:

Topics
	isnan: test for NaN
	laisnan: test for NaN, unoptimized
	ladiv: complex divide
	lapy2: robust sqrt( x^2 + y^2 )
	lapy3: robust sqrt( x^2 + y^2 + z^2 )
	larmm: scale factor to avoid overflow, step in latrs

Detailed Description