Fix bug 7104 - "wide links" and "unix extensions" are incompatible.

Fix bug 7104 - "wide links" and "unix extensions" are incompatible.

Change parameter "wide links" to default to "no".
Ensure "wide links = no" if "unix extensions = yes" on a share.
Fix man pages to refect this.

Remove "within share" checks for a UNIX symlink set - even if
widelinks = no. The server will not follow that link anyway.

Correct DEBUG message in check_reduced_name() to add missing "\n"
so it's really clear when a path is being denied as it's outside
the enclosing share path.

Jeremy.
(cherry picked from commit 9e64c33b7757dd4528a9c8d31d0c0c159a33daf8)