Incorporate changes from robwi repo

[mgreenegit]

Additions have been made to this module in a separate repo:
https://github.com/robwi/xSCSMA

HELP WANTED

If someone would like to review this work and incorporate changes back to the resource kit as a new PR, that would be a great project.

[johlju]

Labeling this as help wanted so that someone in the community can work on these.
There are new resource in robwi repository that should be moved here, and those existing resource should be verified for new functionality.