By Gary Strauss, USA TODAYIf Hollywood handed out Oscars for Best Recent Comeback Among Beaten Down Retailers, J.C. Penney would have been among Sunday night's nominees.J.C. Penney shares are up about 6% to $8.45 in Tuesday afternoon trading for a two-day, 17% gain. That's on top of last week's 25% [pop, after the company posted better-than-expected fourth quarter results and said was on fist-...