mezzaluna: the correct translation is not "crescent moon", but "half moon"
As to crescent moons, we have intriguing entemology of the "croissant" As stated by the aptly-named Charles Paniti:
http://trivial.homestead.com/Panati1.html: Next time you indulge in a croissant with your coffee,
consider this: It's not French--it originated in Austria. The croissant would never have been invented had it not been for some serious bloodshed. It commemorated the 1863 defense of Vienna against invading Turkish troops. What's more, you are committing a kind of oral aggression when you eat it because the crescent shape stands for the similar symbol on the Turkish flag. In the act of eating you are thus devouring someone's enemy. Now put down that bloody piece of bread before you do any more harm.


Note: the web site is an paraphrase of Panati. As I recall, the croissant was not just "commeration": rather, an inventive baker ingeniously seized commercial opportunity in the defeat of a turkish siege.