elnode wiki does not properly validate authentication on GET

[nicferrier]

https://github.com/nicferrier/elnode/blob/master/elnode-wiki.el#L148

this code just checks the cookie, it doesn't check that the cookie is still valid. we need a new function authenticated-p that checks the cookie.

I guess that the authenticated-p function needs to be aware of the authentication scheme because it might not be cookie checking.

[nicferrier]

Not a critical bug I think... if you try and edit the authentication will be checked properly.