Raw Import tool :
- Separate preview and settings implementation from dialog.
In fact the dialog will deseapear and editor will support a widget stack mechanism to display canvas view or tool preview.

This will include all image plugins (but it's not yet done.)!
Note than the settings will be hosted by a new right sidebar tab which will be visible only when the tool running.

This mockup is similar than Risto paper.
I'm sure than Mik will be very impatient to test it (:=)))

-Add Lineary adjustmant using curve widget (as UFRAW).

Still Color management improvements to do to complete RAW Import tool.
Please, let's me more free time...