Adding simple permissions

[Douglas Summers]

As much as I like Flatpak, the ability to make simple changes to the
programs's permissions is severely lacking. I've already had issues
with Okular (refuses to see my printer) and LibreOffice (can't send a
file via email). Now I've tried RhythmBox, which refuses to see any
audio CDs (using a Blu-ray player). While I'm perfectly fine with
Flatpak's sandboxing features (one of the reasons I really like its
concept), I just don't understand why these keep cropping up.