handle update file timestamp option from Setup/Metadata when file are changed...

handle update file timestamp option from Setup/Metadata when file are changed outside metadata, as transformation through icon-view (JPEG files) or when
files are overwritten from Image Editor. BQM already manage this option properly. Import tool is not affected by this settings (as import or export file always preserve file timestamps)
Toogle on option from Setup/Metadata config pannel to on, to prevent all dysfunctions with extra application which use file timestamps to detect automatically file modifications.
BUGS: 329608
FIXED-IN: 4.0.0