GLOBAL MARKETS-Malaysian air crash amplifies move to safer assets

* Crash of Malaysian airliner sparks risk-aversion * Russian assets fall on U.S., EU sanctions * U.S. housing starts weak; Morgan Stanley results up (Updates prices, adds context) By Ryan Vlastelica NEW YORK, July 17 (Reuters) - Stock markets around the world on Thursday were sharply lower and safe-haven investments like gold and government bonds rose after news a Malaysian airlines jet was shot down over eastern Ukraine near the Russian border. Almost 300 people died in th