Rawtherapee: Add Flatpak package

[scriptfx]

https://github.com/flathub/flathub/wiki/App-Submission

Actually Flatpak has better support in major distros then Snap.

[Floessie]

Apart from the fact that this is not really a duty for our development team, I just read that flatpack has some problems.

[Beep6581]

Additionally, we already have AppImages.

[scx]

I created the flatpak package for RawTherapee.

See also:
https://github.com/Beep6581/RawTherapee/issues/5113
https://github.com/flathub/flathub/pull/789

[adds68]

Apart from the fact that this is not really a duty for our development team, I just read that flatpack has some problems.

This is a complete FUD, which has been explained in great details here: https://ramcq.net/2018/10/15/flatpak-sandbox-security/

[scx]

I've provided a single-file bundle for x86_64.
https://github.com/scx/rawtherapee-flatpak/releases

[scx]

I've updated my flatpak package for RawTherapee to version 5.7.
https://github.com/scx/rawtherapee-flatpak
https://github.com/scx/rawtherapee-flatpak/releases
https://github.com/scx/rawtherapee-flatpak/releases/tag/v5.7+20190926
It is worth to mention that it can use GIMP as an external editor. This wasn't possible earlier.

[Beep6581]

@scx since you're dedicated to maintaining the flatpak then seems right that we add it. As I understand it, there is no need for us to host it, as users can get it from some external repository. In preparation for the Linux Repositories page https://github.com/Beep6581/RawTherapee/issues/5462#issuecomment-535386464 , what are the complete steps needed for someone to get and use this flatpak?

[bilelmoussaoui]

The user can get the flatpak version of RawTherapee from Flathub here https://flathub.org/apps/details/com.rawtherapee.RawTherapee

[scx]

I got access to the new repository on Flathub, and just updated the package, so it's now able to open photos in GIMP or any other external editor that has access to the /tmp directory from the host.

If you want to mention the flatpak package, you should refer to this page:
https://flathub.org/apps/details/com.rawtherapee.RawTherapee