Since image files in online help do not depend on the language, they were consolidated in their own directory help/images/. To avoid treating this directory as another language (like e.g. help/en_US/), the language directories were moved to their own subdirectory, i.e. help/en_US/ became help/l10n/en_US/.

Custom online help packages need to move the HTML files accordingly. Relative paths to images and external CSS files need to be adapted by adding ../
Paths in the .spec file need to be adapted for packaging. Debian packaging does not need to be adapted, unless it was modified and now explicitly contains the help paths.