4.0.0: Merge pull request #26 from alexdewar/opencv4

Update for OpenCV >= 4

3.9.0

This release improves the visualization and output of results hen using ROIs. It also fixes several bugs including MacOS compatibility, persistent workspaces...

In addition, a new clustering/filter which allow to cluster together objects of similar colour has been added. This latter feature is the exclusive contribution of Nathanael Lampe(@natl).

3.8.11: Merge pull request #4 from cicku/patch-1

Update opencfu.desktop. Thanks for that!