Last year, I sent an e-mail to Marie Colvin, the London Sunday Times journalist who was killed by government forces in the Syrian town of Homs earlier today. I was hoping to hook up with her somewhere in North Africa, where we were both covering the Arab Spring. I asked her to be careful because things looked complicated and scary in Libya. On February 22—a year ago today—she replied, “I am in Tripoli, any chance you coming this way? Need any help? I’m staying a while, but not sure how long…