build: avoid strerror_r pitfalls
build: avoid strerror_r pitfalls

In particular, this guarantees that virStrerror always gives a
useful result.

* .gnulib: Update to latest, for (lots of) strerror_r fixes.

VenkatDatta/libvirt,novel/fbsd-libvirt,eskultety/libvirt,jeckersb/libvirt,jeckersb/libvirt,andreabolognani/libvirt,bjzhang/libvirt,taget/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,zippy2/libvirt,jeckersb/libvirt,rmarwaha/libvirt,warewolf/libvirt,datto/libvirt,novel/fbsd-libvirt,jeckersb/libvirt,jardasgit/libvirt,shugaoye/libvirt,danwent/libvirt-ovs,jeckersb/libvirt,iam-TJ/libvirt,foomango/libvirt,usc-isi/libvirt,novel/fbsd-libvirt,trainstack/libvirt,emaste/libvirt,trainstack/libvirt,cbosdo/libvirt,rmarwaha/libvirt,taget/libvirt,rlaager/libvirt,andreabolognani/libvirt,trainstack/libvirt,danwent/libvirt-ovs,olafhering/libvirt,iam-TJ/libvirt,wiedi/libvirt,jardasgit/libvirt,zippy2/libvirt,warewolf/libvirt,datto/libvirt,foomango/libvirt,libvirt/libvirt,VenkatDatta/libvirt,taget/libvirt,fabianfreyer/libvirt,eskultety/libvirt,dumbbell/libvirt,zhlcindy/libvirt-1.1.4-maintain,zhlcindy/libvirt-1.1.4-maintain,soulxu/libvirt-xuhj,wiedi/libvirt,shugaoye/libvirt,elmarco/libvirt,leilihh/libvirt,wiedi/libvirt,rmarwaha/libvirt1,leilihh/libvirt,zippy2/libvirt,cbosdo/libvirt,shugaoye/libvirt,olafhering/libvirt,libvirt/libvirt,kantai/libvirt-vfork,soulxu/libvirt-xuhj,dumbbell/libvirt,emaste/libvirt,warewolf/libvirt,elmarco/libvirt,siboulet/libvirt-openvz,fabianfreyer/libvirt,jeckersb/libvirt,iam-TJ/libvirt,cbosdo/libvirt,iam-TJ/libvirt,jfehlig/libvirt,nertpinx/libvirt,nertpinx/libvirt,kantai/libvirt-vfork,usc-isi/libvirt,shugaoye/libvirt,usc-isi/libvirt,agx/libvirt,foomango/libvirt,emaste/libvirt,bjzhang/libvirt,rlaager/libvirt,bjzhang/libvirt,iam-TJ/libvirt,soulxu/libvirt-xuhj,dumbbell/libvirt,agx/libvirt,leilihh/libvirt,danwent/libvirt-ovs,kantai/libvirt-vfork,zhlcindy/libvirt-1.1.4-maintain,VenkatDatta/libvirt,trainstack/libvirt,bjzhang/libvirt,olafhering/libvirt,crobinso/libvirt,dumbbell/libvirt,leilihh/libvirt,wiedi/libvirt,emaste/libvirt,warewolf/libvirt,eskultety/libvirt,olafhering/libvirt,crobinso/libvirt,rmarwaha/libvirt1,jfehlig/libvirt,rmarwaha/libvirt1,kantai/libvirt-vfork,rmarwaha/libvirt,jfehlig/libvirt,elmarco/libvirt,emaste/libvirt,taget/libvirt,siboulet/libvirt-openvz,dumbbell/libvirt,andreabolognani/libvirt,datto/libvirt,wiedi/libvirt,wiedi/libvirt,crobinso/libvirt,rmarwaha/libvirt1,foomango/libvirt,fabianfreyer/libvirt,taget/libvirt,wiedi/libvirt,jardasgit/libvirt,zhlcindy/libvirt-1.1.4-maintain,iam-TJ/libvirt,usc-isi/libvirt,VenkatDatta/libvirt,iam-TJ/libvirt,rmarwaha/libvirt1,cbosdo/libvirt,eskultety/libvirt,datto/libvirt,andreabolognani/libvirt,nertpinx/libvirt,novel/fbsd-libvirt,danwent/libvirt-ovs,novel/fbsd-libvirt,fabianfreyer/libvirt,kantai/libvirt-vfork,datto/libvirt,zippy2/libvirt,leilihh/libvirt,rmarwaha/libvirt,cbosdo/libvirt,siboulet/libvirt-openvz,rlaager/libvirt,agx/libvirt,zhlcindy/libvirt-1.1.4-maintain,novel/fbsd-libvirt,warewolf/libvirt,agx/libvirt,trainstack/libvirt,rlaager/libvirt,nertpinx/libvirt,jfehlig/libvirt,novel/fbsd-libvirt,crobinso/libvirt,warewolf/libvirt,trainstack/libvirt,emaste/libvirt,jeckersb/libvirt,rmarwaha/libvirt,leilihh/libvirt,trainstack/libvirt,soulxu/libvirt-xuhj,agx/libvirt,rlaager/libvirt,rmarwaha/libvirt1,novel/fbsd-libvirt,nertpinx/libvirt,jardasgit/libvirt,eskultety/libvirt,shugaoye/libvirt,libvirt/libvirt,warewolf/libvirt,rmarwaha/libvirt,bjzhang/libvirt,libvirt/libvirt,siboulet/libvirt-openvz,elmarco/libvirt,soulxu/libvirt-xuhj,siboulet/libvirt-openvz,jardasgit/libvirt,novel/fbsd-libvirt,dumbbell/libvirt,usc-isi/libvirt,foomango/libvirt,danwent/libvirt-ovs,emaste/libvirt,elmarco/libvirt,fabianfreyer/libvirt