Create Trilinos GitHub Issue Lifecycle Model
Created by: maherou
Recent activity with GitHub issues suggests we need an explicit issue lifecycle model to communicate expectations for clients, users and developers. This issue results from a query by @mwglass. Others who might be interested are: @jwillenbring @bmpersc and @bartlettroscoe
Also, I have added a new label "process improvement" so we can group issues that have this theme.