* Yen extends rebound after comments about its 'excessive weakness'. * Dollar/yen briefly breaks below key retracement level. * Eurogroup president Juncker says euro is 'dangerously high'. * Euro pulls back from multi-month peaks vs USD, yen. * Dollar/yen falls 0.5 pct, euro/dollar down 0.1 pct. The yen extended its gain for the second day on Wednesday after a warning about its excessive weakness by a Japanese cabinet minister while the euro also slipped after a top European official complained about its recent gains. Traders unwound bearish positions in the Japanese currency after Japan's Economics Minister Akira ... (full story)