Floating point error handling

Setting and getting error handling

seterr([all, divide, over, under, invalid])	Set how floating-point errors are handled.
geterr()	Get the current way of handling floating-point errors.
seterrcall(func)	Set the floating-point error callback function or log object.
geterrcall()	Return the current callback function used on floating-point errors.
errstate(**kwargs)	Context manager for floating-point error handling.