[Gimp-developer] Separate repository for GIMP AppImage plug-ins

[Carmelo DrRaw <aferrero1975 gmail com>]

As you might know, I am providing since quite some time a Linux AppImage package for GIMP, both for stable 
releases and development snapshots.
So far, the AppImages have been shipped in two versions, one only containing the GIMP application, and 
another one also containing several popular plug-ins.

While this worked, the approach had few major drawbacks:
* the size of the package with plug-ins is obviously larger than the one without
* there was no way to decouple the versions of the various plug-ins and the one of the GIMP application

Recently I have managed to decouple the GIMP plug-ins from the main AppImage, and provide them as separate 
packages.

The separate plug-ins are now available from this release page: 
https://github.com/aferrero2707/gimp-plugins-collection/releases/tag/continuous 
<https://github.com/aferrero2707/gimp-plugins-collection/releases/tag/continuous>. 
In the same release page you will also find macOS packages that are compatible with the official GIMP DMG.

In order to use the AppImage plug-ins, you will need to grab the most recent GIMP AppImage packages: 
* 
https://github.com/aferrero2707/gimp-appimage/releases/download/continuous/GIMP_AppImage-release-2.10.10-x86_64.AppImage
* a recent development snapshot like 
https://github.com/aferrero2707/gimp-appimage/releases/download/continuous/GIMP_AppImage-git-2.10.9-20190403-x86_64.AppImage
 (or newer).

The installation of the plugins is very simple:
* download the corresponding AppImage
* make it executable with `chmod +x`
* run it

This will automatically copy the required files into

        $HOME/.config/GIMP-AppImage/2.10/plug-ins

and the GIMP AppImage should correctly find them the next time it is launched.

The plug-ins are updated on a daily basis, so I suggest you to bookmark the release page and visit it 
frequently in order to get the new updates, especially for the G'MIC package!

All this is very recent, so I cannot guarantee it will work 100% OK for all of you.
In case of problems, please report them through the GitHub issue tracker: 
https://github.com/aferrero2707/gimp-plugins-collection/issues.

I hope you will find this helpful!

Andrea