Multiple console support for loader(8)

Hi,

For a while I have been frustrated that the /boot.config -D option only
works for the boot1/2 and has no effect in the loader.

http://www.devrandom.co.uk/freebsd/bootmulti.diff contails patches to
support multiple consoles in the loader, and allows a single -D option
in /boot.config to give dual console support to the bootblocks, the
loader and the kernel.

Before I go ahead and tidy the patches up, document the changes and code
the non-i386 parts, is this something that is wanted? It always seemed
strange to me that boot2 could support dual consoles, while the loader
couldn't even with it's very nice console framework code.

Gavin