Add "Select Multiple Bars" feature in Roadmap Planner widget

Roadmap Planner is the only tool on Wiki to visually display project status.
In case when there is some major change in your project you need to move multiple tasks in the project to new dates. Currently, you need to move each bar separately. Would be great if there will be a feature to select multiple bars and move them together.
From UI perspective it could be similar to select feature in AutoCAD or SketchUp.