Log Message:
Update to 0.60.0
  pkg_update_src_summary:
     - Fix for the case when there are no updated/new packages, but
       removals exist.
     - Resulting summaeries are postprocessed by pkg_summary2bb_pkgs.
     - Option -v was added

  pkg_subgraph_deps:
     - Fix for option -1

  pkg_digger:
     - Minor fix. -sf outputs both fields and strategies.
     - All pkg_digger(1) backends return plain summaries on -1|-3|-9.
       Option -r was removed from pkg_digger_{summary,installed}

  pkg_digger_summary:
     - Implementation for option -n.

  pkg_summary2bb_pkgs:
     - Additional error checks.

  Man pages for pkg_digger, pkg_digger_summary, pkg_digger_installed
  were updated.