Update to Traits 4.3.0

Requires changing 'import enthought.traits...' to 'import traits...'  Because of this it's kind of an API incompatibility.

Previous aborted pull request problem with an infinite loop in util/dep.py was caused by invalid user config when attempting 'plugin makedist'.  Code now protected from looping.

Includes some protections from empty job_name resource values found by a user at ARC.  Also includes some code to protect against the GUI crashing when a project can't be found.

Other than that, some minor edits for quieter pylint output.