(Reuters) - London's FTSE 100 inched up on Thursday, led by an earnings-driven 5% rise in Smith+Nephew, while sharp gains in price comparison website Moneysupermarket.com and electrical engineering firm Spectris helped midcaps outperform.The blue-chip index added 0.2%, with Smith+Nephew hitting a more than four-month high after the medical products maker topped annual sales expectations for 2019 and forecast another year of revenue growth.The FTSE 250 rose 0.4%. Moneysupermarket.com , which..