BRANCH 4.2-021:
  passed the search_key of each bar to GanttCbk so it doesn't have to rely on index to save the dates for each gantt bar
  added sorting of the bars according to pipeline order if the gantt bars search type is sthpw/task
Merge branch '4.1-021' of https://github.com/southpawtech/TACTIC-DEV into 4.1-021