getxattr/setxattr

[Steve French]

I was prototyping a new T2 infolevel that better matches the getxattr 
and setxattr VFS calls.

Any objection to using the next QPathInfo/SetPathinfo infolevel in 
sequence after the POSIX Get and Set ACL ones?  and defining a new Unix 
QFSInfo capability 0x4  for the server to indicate support for xattr 
support (only two are defined at the moment, which includes the POSIX 
ACL capability).   This would allow the client to send the actual xattr 
name (including the namespace prefix) to Samba (needed for trusted and 
security xattrs among others including support for security labels and 
presumably would be required for remote support of SELinux).