Seoul shares up 0.8 pct on shipyards, Samsung Elec

* KOSPI rises 0.8 pct helped by U.S. GDP data, foreign buying * Samsung Electronics gains after Q3 results; caution on Q4 * Shipbuilders rally after losses; Daewoo up on order hopes (Updates to mid-morning) SEOUL, Oct 30 (Reuters) - Seoul shares rose on...