staging is a safety net, not a trampoline

[Graham Percival]

Guys,

We've had a bunch of patches breaking staging now.  This is
problematic because it holds up other patches from getting into
master.  In turn, this holds up a release because I feel weird
about making a release when there's half a dozen patches waiting
to go into master.  And right now, this holds up widespread
testing of various release-critical fixes for GUB.

Patchy is supposed to be a *safety* net, not a trampoline.  The
idea is not to jump up and down on it.

I know that building the documentation is a hassle.  I know that
it may or may not properly track the dependencies.  I know that
the messages may not be as informative as they could be (although
I really benefitted from Phil's recent logfile work to find the
most recent breakage in staging).

But please consider testing your patches a bit more before sending
them in.

- Graham