without the file extension. This part of the file path is removed from
the multi-field url_paths_sxt, which has now not the file name as last
part of the path list.
The same applies to the new fields source_file_name_s and
target_file_name_s in the webgraph schema.
- create a load list from the current list of known hosts
- do not create this list for each Balancer.pop access
- create the list from those hosts which have a zero-waiting time
- select 1/3 from that list which have the most urls waiting
- get hosts from the wainting list in random order
- fixes for some delta-time computations
- always load all urls from hosts which have never been loaded before