merge from devel to master to create release 68.3.0#686

Merged

mgcam merged 5 commits intomasterfrom devel

May 14, 2020

+133-36

Commits on May 12, 2020

- consider negative and positive controls
mgcam
committed

Commits on May 13, 2020

Commits on May 14, 2020

Changes file update for release 68.3.0
mgcam
authored