Heads-up: pari 2.7 update in Rawhide

[Paul Howarth]

I'm about to build pari 2.7.1 in Rawhide, which includes an soname bump 
and has API changes that will need fixes in many of the handful of 
packages that use it. I've already been in discussion with the 
maintainers regarding this, and it seems best to have the new version 
available in Rawhide to work on.

To mitigate the disruption this will cause, I'm temporarily including 
the old library in the package, so there won't be broken deps whilst the 
migration process takes place.

Paul.