By Marc Jones LONDON (Reuters) - World shares dipped on Friday as investors locked in profits at the end of what was set to be the second best week of the year for stocks, while the dollar held near a four-year high against the yen. A radical monetary stimulus plan from the Bank of Japan and signs of a growing recovery in China have spurred a near 3 percent jump in the MSCI world share index this week and sent the yen tumbling. As investors booked some of those sharp gains, a small 0. ...