Export: global options: allow upscaling & high quality resampling

[g-man]

Also, see:

Warning about darktable dev releases

There is more and more people using the dev release, and that’s fine. This ensure that the new features are tested early and we get bug report in time for the releases. But just remember that even if we try hard to keep compatibility with old edits, it may be possible that on the dev releases we break compatibility if for example keeping two slightly different algorithms would require too much maintenance. Have all and happy new year with darktable !