He took a mulligan

Does anyone know the origin of this expression? It's the punch line at the end of today's 'Wizard of Id' cartoon, which I've uploaded to: http://tinyurl.com/hhi0

I looked up the expression at:

http://www.bartleby.com/61/22/M0472250.html

...and get the general idea of its meaning, but where on earth did it come from? A 'mulligan' is a kind of stew made from odds and ends of food, according to:

http://wordreference.com/english/definition.asp?en=mulligan

How did a kind of stew end up as a golfing expression?

-- Christopher

http://alt-usage-english.org/AUE_gallery/chris_johnson.html