Detect Loop Conditions

[fireproofsocks]

You create a race condition that triggers a PHP memory error if you do something like use getProductImages to query for and format a list of images, but then the formatting Chunks include more instances of getProductImages.

This is probably too obscure to really merit hacky prevention/protection, but it would be nice for the user/developer if this condition could be detected.

Note this problem is not specific at all to Moxycart.