virsh: allow empty string arguments
virsh: allow empty string arguments

"virsh connect ''" should try to connect to the default connection,
but the previous patch made it issue a warning about an invalid URI.

* tools/virsh.c (VSH_OFLAG_EMPTY_OK): New option flag.
(vshCommandOptString): Per the declaration, value is required to
be non-NULL.  Honor new flag.
(opts_connect): Allow empty string connection.

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