EXCLUSIVE: A major pre-emptive spec-script deal has just closed, with Amy Pascal’s Pascal Pictures acquiring Christopher Cosmos’ American Rebel. It is based on the true story of Deborah Sampson, who risked her life during the Revolutionary War by disguising herself as a man and joining the Continental Army. We’re hearing that the deal is for high-six figures for the tale that reads like an American version of Mulan; the spec was a buzzy item around town this week that has…