Read an extended log even if cs-uri is split over several columns

Read an extended log even if cs-uri is split over several columns

Sarg used to require that the visited URL be stored in column cs-uri of the
extended log format. But the URL can be split over the cs-uri-scheme,
cs-host, cs-uri-port, cs-uri-path and cs-uri-query columns.

Sarg detects the columns and re-create the full URL if cs-uri is not
found.