Title: #189: SELINUX: Use getseuserbyname to get IPA seuser
@jhrozek this patch replaces function from libsemanage with function from libselinux...
The commit message says that libselinux is recommended over libsemanage by SELinux
developers. If that is the case, I think it makes sense to use the preferred version. So I
would not close this PR. Also this patch removes more code than it adds, which is
See the full comment at https://github.com/SSSD/sssd/pull/189#issuecomment-319019703