Release Note: jarsigner Preserves POSIX File Permission and symlink Attributes

When signing a file that contains POSIX file permission or symlink attributes, `jarsigner` now preserves these attributes in the newly signed file but warns that these attributes are unsigned and not protected by the signature. The same warning is printed during the `jarsigner -verify` operation for such files.

Note that the `jar` tool does not read/write these attributes. This change is more visible to tools like `unzip` where these attributes are preserved.