+ Remove this module, functionality move to rez.util and rez.env.
+ Logic moved to rez.env.
+ Reimplement the logic from rez.cli._util to retrieve the current context file.
+ Update to use relocated code.
+ Update to use relocated code.  Also improve logic to catch a non-existant current rxt (either not set or deleted).
+ Functionality to view and write a graph.
+ Change option to fail graph.
+ Update based on changes to build process.
+ Fix a problem with the import.