Update WHATSNEW.txt to explain the vfs_widelinks module addition.

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>

Autobuild-User(master): Ralph Böhme <slow@samba.org>
Autobuild-Date(master): Thu Apr  9 21:21:46 UTC 2020 on sn-devel-184

WHATSNEW.txt

@@ -27,6 +27,30 @@ we test with in our CI infrastructure.
 (Build time support for the file server with Python 2.6 has not
 changed)
 
+wide links functionality
+------------------------
+
+For this release, the code implementing the insecure "wide links = yes"
+functionality has been moved out of the core smbd code and into a separate
+VFS module, vfs_widelinks. Currently this vfs module is implicitly loaded
+by smbd as the last but one module before vfs_default if "wide links = yes"
+is enabled on the share (note, the existing restrictions on enabling wide
+links around the SMB1 "unix extensions" and the "allow insecure wide links"
+parameters are still in force). The implicit loading was done to allow
+existing users of "wide links = yes" to keep this functionality without
+having to make a change to existing working smb.conf files.
+
+Please note that the Samba developers recommend changing any Samba
+installations that currently use "wide links = yes" to use bind mounts
+as soon as possible, as "wide links = yes" is an inherently insecure
+configuration which we would like to remove from Samba. Moving the
+feature into a VFS module allows this to be done in a cleaner way
+in future.
+
+A future release to be determined will remove this implicit linkage,
+causing administrators who need this functionality to have to explicitly
+add the vfs_widelinks module into the "vfs objects =" parameter lists.
+The release notes will be updated to note this change when it occurs.
 
 REMOVED FEATURES
 ================