borders: cartier style framing
Revert "borders: cartier style framing"

This reverts commit 54a4c60b12bb3d44fe32147616d9b0681df3c3f0.

Whoops string freeze :( Reapply after release...
lens correction: more consistent behavior of gui and auto-detection
fix for #9290
hotpixels: be less trigger happy
monochrome: avoid saturation artifacts with a more generous default
[usermanual] Allow translated drafts
Another break of string freeze

Revert after the release!
Compute watermark scale based on larger side of image.

This is to have the same watermark size for landscape and portrait
picures. This way it is possible to export a set of picures with
a style having a watermark and keep a constant size for the watermark.
Add different ways to compute the watermark scale.

It is now possible to chose the scale to be relative to the image,
the smaller border and the larger border. Only the two last options
are independent of the image orientation.
WIP
WIP
WIP
Rework the watermark rendering.

This version does not use constant literal anymore. It introduces three
mode for the watermark placement.

image :          this is as before, alignement/scale are based on the image
                 width and depends on the image orientation.

larger border  : the alignement/scale are computed based on the larger border

smaller border : the alignement/scale are computed based on the smaller border

The last two modes can be used in styles are independant of the actual
image orientation. This new implementation try to be cleaner by using
most of the time original image coordinate. It should be easier to
maintain.