Machine maintainer responsibility description.

["Carlos O'Donell" <carlos at redhat dot com>]

I have rewritten the machine maintainers section to read thusly:

~~~
A machine maintainer is responsible to the GNU C Library project
for maintaining the support for their machine, and for supporting
the users of that machine. In general this maintainership means
that you have the discretion to assume consensus for a change of
your own without waiting for review or comments on consensus. If
the discussion shows there is no consensus after all then your
change will need revising or reverting. This does not mean that 
all objections are relevant for establishing lack of consensus, 
e.g. if the reasons given are speculative, based on false analogies
to other machines or a lack of understanding of the change and
its context or themselves ignore other established consensus.
Lastly keep in mind that sustained opposition may be ignored if
it is not considered a substantial issue by an important part
of the concerned developers.
~~~

This language comes largely from Joseph Myers' comments, which
I felt were the best summary of all responses.

In my opinion the new language addresses some of the worries that
other developers had around the original proposal, relaxing the
veto language, and at the same time clarifying when an objection
may or may not be relevant.

This language is nothing so formal as a contract, but think on
it like a reminder. That when you're looking at comments from
community reviewers you should consider:

Do I have consensus?
https://sourceware.org/glibc/wiki/Consensus

What are my responsibilities?
https://sourceware.org/glibc/wiki/MAINTAINERS#Machine_maintainers

Cheers,
Carlos.