9P/SELinux: management of scon via TAUTH

Change-Id: I328b06e00a527b876277169e24cb099427eb6d28
Signed-off-by: Philippe DENIEL <philippe.deniel@cea.fr>
9P: brings information from export manager down to 9p protocol layer

Change-Id: I8fa711ddc70731b9d6b4fdf54b4e1842f2621c7e
Signed-off-by: Philippe DENIEL <philippe.deniel@cea.fr>
SElinux: make security option "selinux" printable by StrExportOptions()

Change-Id: Ife22b14638dd64edfb448be73d40b51d2cfcbea8
Signed-off-by: Philippe DENIEL <philippe.deniel@cea.fr>