Hmm, this actually seems like it contains a bug: if focus is in an inline editor, and the inline editor's language changes, then we won't update anything.  Seems like we'd need to listen to the per-Document `"languageChanged"` event instead to really do this right.  The status bar does change contexts when you're in an inline editor, so it _is_ possible to switch that document's language without having to open it in a full editor first.

Btw, if fixing this makes the new `"currentDocumentLanguageChanged"` event unneeded, then we might as well back that out too just to keep the scope cleanly minimized...