Add check test of avoidSelfInteractionMask based on Luc's, Jan's and Bruno's work.
Add check test of avoidSelfInteractionMask based on https://answers.launchpad.net/yade/+question/682290
Edited by Janek Kozicki
Add check test of avoidSelfInteractionMask based on https://answers.launchpad.net/yade/+question/682290