Escape all remaining reserved chars in direct_fog_url

URI regexp pattern for rel_segment
      RESERVED = ";/?:@&=+$,\\[\\]"
      rel_segment   = ( unreserved | escaped |
                          ";" | "@" | "&" | "=" | "+" |
                          "$" | "," )
Use Addressable::URI.escape in direct_fog_url

URI.escape is deprecated for usage with paths, Addressable::URI is
recommended instead.