Catch setting tooltip for non-existant key.
Merge remote branch 'upstream/master' into fix.empty_stash
rose metadata-graph: add index in doc/command.html
Merge pull request #1212 from benfitzpatrick/rose-metadata-graph.doc-cli-index

rose metadata-graph: add index in doc/command.html
Merge pull request #1208 from arjclark/fix.empty_stash

Fix stash widget starting from empty