Manifests with multiple empty lines between sections are rejected by
JDK1.2. Such format is legitimate in 1.1, and the jar tool in 1.1 can
generate manifests in such format. We should make 1.2 compatible with
1.1 at least on this.

For empty lines between global attributes or within a section, which is
also accepted by 1.1 and rejected 1.2, see bug 4110104.