Add support for the dump_data operation

[mjg]

dump_data is required for bringing the package impressive back to life in Fedora where pdftk has been killed off because of its use of libgcj.

[vog]

Thanks for pointing this out!

Where exactly is pdftk used in the impressive tool? It seems to create PDF files "from scratch", not to fill out forms.

Also, according to https://ask.fedoraproject.org/en/question/65261/pdftk-not-in-f21/ it seems that the iTextpdf library is considered nonfree by Fedora? Why is that? What's wrong with the AGPL version of iTextpdf?

[mjg]

impressive doesn't create PDF files. It is a presentation tool which adds features beyond "page forward/backward". It uses pdftk as a tool to analyze pdf files, and it needs basically two features: uncompressing a compressed stream and some structure info (pages, bookmarks etc.) that dump_data provides.

As for Fedora's decisions, I don't understand them but https://lists.fedoraproject.org/pipermail/devel/2014-March/196394.html may help. I'm afraid that libgcj is the major issue (compared to iText).

I'm just the maintainer of the Fedora package for impressive, but I'm looking for ways to get the functionality that impressive needs in a package that is fit for Fedora's guidelines. (I'm not sure whether mcpdf would meet them, though.)