BERLIN: The leader of Germany’s Free Democrats (FDP) resigned on Monday after the party’s worst-ever election defeat, which saw it kicked out of parliament where it was junior partner to Chancellor Angela Merkel’s conservatives. Outgoing vice chancellor Philipp Roesler, who quit as head of the pro-business party, and foreign minister Guido Westerwelle are among the cabinet members who lost their seats in the party’s ballot box disaster. “It is the heaviest and worst defeat in the history of the party,” said…