Issue with prototype.js

[TheMoogster]

Hi

I have found a bug on websites running any version of prototype.js
The bug occurs in the Utils.size method were it returns 37 on an object with two "custom" properties (two cohorts).
(It should return 2, as it does on a website without prototype)

The fix is easy:
size: function(object) {
return Object.keys(object).length
},