updated to current ci but base_url() defect

I was able to fix it by going into system/core/Config.php and changing __construct to do it the old way, using  $__SERVER['HTTP_HOST'] instead of the new, non-working way which used $__SERVER['SERVER_ADDR']

Hasn't been thoroughly tested yet but works so far.

Now that I've gotten a way into the site I get a new error:

Call to a member function unset_userdata() on null

Strange stuff.