News roundup: Comcast takeover of Time Warner Cable could reshape pay TV … White House unveils cybersecurity guidelines for companies … Retail sales in U.S. unexpectedly fell 0.4% in January

It's a big deal: Comcast Corp.'s proposed $45.2 billion takeover of Time Warner Cable Inc. would combine the country's top two cable providers into a colossus that could reshape the U.S. pay TV and br…