Add IP, PORT and REFERER to log output options
Update Logger to handle empty referer field

Currently a warning is written to the web server log if the logger tries
to access the HTTP_REFERER index on $_SERVER and it's not present (e.g.
when a user refreshes or comes to the page from a bookmark).  This fix
checks first to make sure the referer is set.
Implement Iterator interface on EmptyObject

Removes the need to check length on something returned by a $dom
selector - and ensures no weblog errors if you forget-to.
Merge pull request #169 from 8w/8w-EmptyObject-Iterable

Implement Iterator interface on EmptyObject
Merge pull request #168 from 8w/8w-add-logger-tokens

Add IP, PORT and REFERER to log output options
Merge branch 'master' into live