Require texinfo 4?

[Hans-Peter Nilsson]

Hi.

Nick was kind enough to do basic adjustments in the
documentation for MMIX to match the version of texinfo used in
the other docs (though that's not how it was expressed ;-)
supposedly lower than the 4.0 (released in 1999!).

I'd like to "raise the bar" and require texinfo 4.0 when
regenerating docs.  This is just a maintainer-mode issue.
I wanna use @anchor+xref and @url and GCC requires texinfo 4.0
anyway.  Not fair! (sniff :-)

Comments?

brgds, H-P