2.13 started now; change everything!

[Graham Percival]

Hi all,

I'm starting a new thread for extra visibility.  I've just
officially started the 2.13 branch.  We now accept[1] patches
which change the input syntax, change the build system, change the
build requirements, and generally break everything[2].

[1]  By "accept", we mean "will review eventually".

[2]  By "break everything", we mean "may introduce some slight
incompatibilities which you promise to fix in the Very Near Future
(tm) and we trust you sufficiently to believe that you will
actually do this".


Cheers,
- Graham