Minor changes for simpler plug and play with 3rd party libs

A couple of changes we needed...

1 - The "cookies" method was overridden by a third party gem which doesn't support symbol lookup, so I've used a slightly more exact lookup. More fool them, I'll raise a bug there.

2 - CanCan aggressively prevents the accept action (indeed, any action it isn't aware of), which isn't necessary in this case.

I've submitted this pull request simply to make our lives easier, but they are backward compatible and may help others (especially the CanCan one).

Cheers!