KEY TAKEAWAYSSpirit Airlines shares are surging 12% in premarket trading Friday after the discount carrier said it plans to cut jobs and sell some planes as it tries to shore up its finances.The company said that as part of its plans "to return to profitability," it has identified around $80 million in cost cuts that it plans to start implementing early next year. Spirit also said it had entered into a deal to sell 23 A320ceo/A321ceo aircraft for around $519 million to aircraft-maintenance and component ser ...