LONDON (Reuters) - Europe may need to sacrifice Greece's membership of its single currency bloc in order to convince Germany to put in more money to save the euro, Chancellor of the Exchequer George Osborne suggested in remarks certain to enrage euro zone leaders. As the EU's biggest economy and largest contributor, Germany holds the key to how the bloc can rescue its troubled, smaller economies and whether Europe is able to agree on a banking union to end 2-1/2 years of debt turmoil. ...