- If all extension specified and an wrong extension is written or
no extension written, save with the first allowed extension.
- If all extension specified and a good extension is written, save as usual.
- If an extension is specified and a wrong extension is written, an error pop-up
will show.
- If an extension is specified and no extension is written, save with the
specified extension.

--HG--
branch : fw4spl_0.11.0