New York (AFP) – The so-called “poison pill” Twitter has proposed to use against Elon Musk’s potential hostile takeover is a mechanism with a proven track record that could force the outspoken entrepreneur into negotiations. To halt a takeover, the board plans to activate the pill if the Tesla CEO comes to own more than 15 percent of Twitter. He already holds 9.2 percent of the company, and said Thursday he has ready the $46.5 billion necessary to make an offer for the rest. Such a “pill” would allow other Twitter shareholders to purchase shares at half price, increasing the amount of share…