Yes, a contributors file should be added, maybe also a AUTHORS file that lists the copyright holders?
like
http://golang.org/CONTRIBUTORS
http://golang.org/AUTHORS
http://golang.org/LICENSE
Another alternative: Copyright (c) 2014 The OxyPlot Authors.
Should there be a CLA?
http://en.wikipedia.org/wiki/Contributor_License_Agreement
like
http://golang.org/CONTRIBUTORS
http://golang.org/AUTHORS
http://golang.org/LICENSE
Another alternative: Copyright (c) 2014 The OxyPlot Authors.
Should there be a CLA?
http://en.wikipedia.org/wiki/Contributor_License_Agreement