Organisers of a Republican event withdrew frontrunner Donald Trump's invitation after he suggested that a presidential debate moderator was tough on him because she was menstruating.The off-handed comment unleashed a new storm of criticism against Trump as he seeks the party's nomination for next year's election and leads in the polls.The bombastic billionaire came under fire from his party after a particularly crude accusation that Fox News' Megyn Kelly - one of the moderators at Thursday's Republican presidential debate - singled him out with rough treatment.Trump had already called out the station's moderators for asking 'unfair' questions after Kelly brought...