Up non-free-firmware priority from low to high

The current situation is that debian.org proudly states "Debian is a complete Free Operating System!" with a big Download link. That link then serves the user an installer of Debian+proprietary firmware. That installer then proceeds to install the proprietary firmware without prompting. Many of us do not find this acceptable.

It turns out that there is already a prompt about non-free firmware (the repository, wholesale)... if only the user chose to "expertly" configure their system.

User "cheapie" on IRC reports that he "keeps running into users over and over again who seem to /not/ want firmware packages installed," and because of that, "would personally prefer for the priority to be high."

Other users are also puzzled why Debian /seems/ to have decided to only allow rejecting the non-free components via the even more expert, hardly documented, boot flag mechanism.

I suggest that it is not an "expert" decision to choose freedom. The user downloaded what loudly purports to be Free Software, so they ought to be offered a choice to get that. Furthermore, it's just the right thing to do, for their freedom's sake.

This MR is at the request of @stappers on the mailing list.