Zywave, the largest software-as-a-service company in the Milwaukee metro, has acquired Chicago software company Code SixFour. Terms of the deal were not disclosed. The acquisition is Zywave's first in about a year, since it bought Norwalk, Conn.-based HR360 Inc., a provider of human resources and benefits compliance software. It also marks the first major move under new CEO Jason Liu in his quest to double the company's size within the next three to five years. Zywave employs a little less than...