Resolves the following issues:
- For the first time you save a .blend file, there was no feedback.
- If the file fails to save (eg "No space left on device") the status
bar message replaces the error with an invalid "Saved" message.
While there is a popup, the user may cancel it with mouse motion
and be left with the status bar message saying the file saved.
D7371 by @XDroid with edits.
1c58311440