FOR BOSSES and boards, dealing with the odd activist shareholder is par for the course. Contending with a swarm of such gadflies is unusual. Last October Starboard Value, an activist hedge fund, took a “significant” stake in Salesforce, a maker of customer-management software, arguing that the firm had failed to convert its leading market position into juicy margins and needed to cut costs. On January 4th Salesforce duly announced it…