Math functions (sqrt, etc.), O(1) work

Topics
	ceil(x/y) and ceil(x/y)*y
	sqrt
	NAN and INF checks
	complex number support
	In C++, including magma_operators.h defines the usual unary and binary operators for complex numbers: +, +=, -, -=, *, *=, /, /=, ==, !=.

Detailed Description