link progress period start date to end date of initial period

[azvoleff]

In 15.3.1 summary tool add a checkbox (on by default) linking the start date of progress period start date to the end date of the baseline period. If unchecked, don't calculate the progress layer, only the summary statistics for each period

[andersan]

@azvoleff is this still a priority? I'm looking for a good first issue to tackle on this project.