security: update user and group parsing in security_dac.c
security: update user and group parsing in security_dac.c

The functions virGetUserID and virGetGroupID are now able to parse
user/group names and IDs in a similar way to coreutils' chown. So, user
and group parsing in security_dac can be simplified.

jeckersb/libvirt,novel/fbsd-libvirt,jfehlig/libvirt,bjzhang/libvirt,siboulet/libvirt-openvz,iam-TJ/libvirt,jeckersb/libvirt,bjzhang/libvirt,jardasgit/libvirt,elmarco/libvirt,trainstack/libvirt,cbosdo/libvirt,rlaager/libvirt,datto/libvirt,jfehlig/libvirt,trainstack/libvirt,taget/libvirt,zhlcindy/libvirt-1.1.4-maintain,shugaoye/libvirt,jeckersb/libvirt,bjzhang/libvirt,rlaager/libvirt,datto/libvirt,rlaager/libvirt,nertpinx/libvirt,iam-TJ/libvirt,novel/fbsd-libvirt,taget/libvirt,zippy2/libvirt,emaste/libvirt,datto/libvirt,trainstack/libvirt,olafhering/libvirt,taget/libvirt,fabianfreyer/libvirt,zhlcindy/libvirt-1.1.4-maintain,jeckersb/libvirt,zhlcindy/libvirt-1.1.4-maintain,iam-TJ/libvirt,jardasgit/libvirt,andreabolognani/libvirt,novel/fbsd-libvirt,trainstack/libvirt,crobinso/libvirt,nertpinx/libvirt,andreabolognani/libvirt,eskultety/libvirt,shugaoye/libvirt,jeckersb/libvirt,fabianfreyer/libvirt,rlaager/libvirt,zhlcindy/libvirt-1.1.4-maintain,elmarco/libvirt,novel/fbsd-libvirt,libvirt/libvirt,zippy2/libvirt,fabianfreyer/libvirt,libvirt/libvirt,rlaager/libvirt,VenkatDatta/libvirt,emaste/libvirt,zippy2/libvirt,siboulet/libvirt-openvz,novel/fbsd-libvirt,eskultety/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,olafhering/libvirt,nertpinx/libvirt,iam-TJ/libvirt,nertpinx/libvirt,emaste/libvirt,emaste/libvirt,eskultety/libvirt,elmarco/libvirt,cbosdo/libvirt,emaste/libvirt,cbosdo/libvirt,eskultety/libvirt,novel/fbsd-libvirt,cbosdo/libvirt,cbosdo/libvirt,jeckersb/libvirt,andreabolognani/libvirt,novel/fbsd-libvirt,shugaoye/libvirt,bjzhang/libvirt,trainstack/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,libvirt/libvirt,shugaoye/libvirt,shugaoye/libvirt,olafhering/libvirt,datto/libvirt,elmarco/libvirt,jardasgit/libvirt,andreabolognani/libvirt,trainstack/libvirt,libvirt/libvirt,crobinso/libvirt,novel/fbsd-libvirt,elmarco/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,agx/libvirt,jeckersb/libvirt,taget/libvirt,bjzhang/libvirt,olafhering/libvirt,agx/libvirt,iam-TJ/libvirt,agx/libvirt,emaste/libvirt,crobinso/libvirt,jfehlig/libvirt,andreabolognani/libvirt,taget/libvirt,agx/libvirt,iam-TJ/libvirt,nertpinx/libvirt,trainstack/libvirt,novel/fbsd-libvirt,siboulet/libvirt-openvz,emaste/libvirt,siboulet/libvirt-openvz,agx/libvirt,eskultety/libvirt,siboulet/libvirt-openvz,zippy2/libvirt,iam-TJ/libvirt,datto/libvirt,zhlcindy/libvirt-1.1.4-maintain,jardasgit/libvirt,VenkatDatta/libvirt,crobinso/libvirt,jardasgit/libvirt