[MAINTENANCE] Fix license comments

[beatrycze-volk]

No description provided.

[stweil]

As far as I know the DFG Viewer is licensed by GPL 3. This pull request relaxes the license by adding GPL 2 to files which did not have a license statement or by changing an existing license statement from GPL 3 to GPL 2.

I don't think that such changes are compatible with the license requirements.

In addition, the PR changes copyright comments. Unless the old comments were wrong, this can be considered bad style or even not allowed.

[beatrycze-volk]

As far as I know the DFG Viewer is licensed by GPL 3. This pull request relaxes the license by adding GPL 2 to files which did not have a license statement or by changing an existing license statement from GPL 3 to GPL 2.

In the files there is no change from 3 to 2. The old version of the text also contains number 2. The only change is the copyright comment.

I don't think that such changes are compatible with the license requirements.

In addition, the PR changes copyright comments. Unless the old comments were wrong, this can be considered bad style or even not allowed.

The DFG Viewer is developed by many developers but in the copyright notice were only mentioned the first ones. The code base itself is managed by the SLUB so this change looks like the one which corrects to the factual state.

[stweil]

In the files there is no change from 3 to 2.

Is this here (and several more) no change from 3 to 2?

[stweil]

The DFG Viewer is developed by many developers but in the copyright notice were only mentioned the first ones. The code base itself is managed by the SLUB so this change looks like the one which corrects to the factual state.

Most old copyrights are for SLUB developers, so a change from individual to an organisational copyright can be done.
But what about the other copyrights which were for Kitodo e. V.? Where did they come from? Were they wrong? If not, it might be better to simply keep them and add a 2nd copyright for SLUB.