If "visibility" flag is not available for some object it MUST be assumed to be true

[ChristianRedl-TomTom]

Fix according to osm protobuf definition.

   // The visible flag is used to store history information. It indicates that
   // the current object version has been created by a delete operation on the
   // OSM API.
   // When a writer sets this flag, it MUST add a required_features tag with
   // value "HistoricalInformation" to the HeaderBlock.
   // If this flag is not available for some object it MUST be assumed to be
   // true if the file has the required_features tag "HistoricalInformation"
   // set.

[akashihi]

@ChristianRedl-TomTom There are more changes than just fixing visibility flag issue. Could you please describe your intentions? For example what was the reason of queue size change?