No idea where a null comes from, but anyway...

- Now showing and converting lags according to the lag format
- Extended im_timesheet_task_dependencies by diff_format_id
  and created  categories for representing lag formats
- Fixed saving and loading dependencies in REST
  /intranet-rest-data-source-procs.tcl and
  project-task-tree.json.tcl

- Disabled anything except Finish-to-Start dependency in
  the GanttSchedulingController
- Still need to adapt display in GanttBarPanel

- Fixed permission issue creating Gantt tasks of a customer
  who is PM of a project

  to be preceeded by a "return"

  SQL storage, so there will be a deterministic update
  order.
  This fixes a bug in cosine where im_projects was updated
  after im_timesheet_tasks, thus overwriting the percent_
  completed values set by a trigger on im_timesheet_tasks

- Added ns_log Error statements

  JSON messages can't have multiple lines...

  faking users

  Added feature to load partial trees, as used by Sencha