LONDON, MADRID | Ireland and Greece appear this week at the opposite ends of the rainbow. Santander credit research team painted Thursday an optimistic picture in its investors’ note based on the news that LHC.Clearnet has cut down by 10pc the additional margin it requires, which was 25pc, for positions in Irish government bonds cleared through its RepoClear service. A more relaxed market environment has also prompted Ireland to increase asset sales to €3…