Add an optional 'phone home' feature to notify users about new versions of GIMP available
It looks like a lot of users rely on outdated versions of GIMP. Sometimes it's because they don't like updates, but sometimes it's because they don't follow news on the website and/or don't read us on social media.
We could improve that by adding a simple 'phone home' feature that would compare the currently installed version of GIMP to the latest version of GIMP and tell the user an update is available.
For that, we could reuse the existing org.gimp.GIMP.appdata.xml file, in particular, that part of it:
<releases> <release version="2.10.8" date="2018-11-07"> <description> <p> GIMP 2.10.8 is mostly a bug fix and optimization release. In particular, it includes: </p> <ul> <li> Adaptative chunk size when rendering projections, improving responsiveness dynamically </li> <li> Detection of RawTherapee (version 5.5 and above) improved on Windows </li> <li> XCF compatibility information in the Save dialog more understandable and discoverable </li> <li> Various performance log tools added and log recording made available in the Dashboard dock </li> </ul> </description> </release>
So we could not only show the new version availability, but also list changes.
This would be a ./configure switch, so that we would build this for our .exe and .dmg, but Linux distributions would disable this (for obvious reasons).