Set different page cache ID based off of cookie that is set from a custom organic group module.

Long story short, this is more in the spirit of the GPL then a request to get this code in.

Issue:
We set a location cookie that changes the sites content & ads based off of user location. location is set via cookie that is a reference to a nid of an organic group. Quick way to make this work is to include the cookie value in the cid when table is equal to 'cache_page'.