improve kde (plasma 5) integration with kmozillahelper

[ianas]

most Linux distro's include an extra package called kmozillahelper that integrates KDE's dialogs in Firefox's open/save menu's
https://github.com/openSUSE/kmozillahelper
as far as I can tell it's a binary blob that use to be shipped as an xpi addon but now it's a shared object
https://software.opensuse.org/package/kmozillahelper
https://aur.archlinux.org/packages/kmozillahelper/
the ubuntu devs have the same package under a different name
https://launchpad.net/~plasmazilla
https://github.com/plasmazilla/mozilla-kde-support
I was hoping maybe you could integrate this in Basilisk for Linux for us KDE users

[Moonchild]

I'm sorry but we already have enough widget code for different desktop interfacing as it is in our tree. Pale Moon and Basilisk are GTK applications; as such they will use by default what the toolkit prescribes. Changing that specifically for a different desktop environment in the core would mean required maintenance and support for it by us as well -- we can't do that, so it'll have to remain an extension.
Considering our plans for maintaining classic/XUL extensions, there shouldn't be an issue continuing to provide it through external code in the same way as plasmazilla.