GLOBAL MARKETS-Stocks reverse losses but markets wary over growth

* European stocks reverse losses, cheap oil lifts airlines* Dollar retreats broadly on concern over global growth* Trade data ease worries over China slowdown(Updates prices, adds fresh quote)By Nigel StephensonLONDON, Oct 13 (Reuters) - European stocks reversed early losses on Monday as airline shares gained after crude oil prices fell to near a four-year low, though broad dollar weakness and a j