Microsoft (MSFT) might make its own smartphone, just as it's decided to build its own tablets, an analyst says. Nomura analyst Rick Sherlund says industry sources have told him that Microsoft may be working with a contract manufacturer to develop its own handset for its Windows Phone 8 software release. This would further ratchet up its competition with Apple (AAPL) and Google (GOOG). "It is unclear to us whether this would be a reference platform