Common header files:
               - iscsi_ifev.h (user/kernel events).
               - iscsi_if.h (user/kernel #defines);
               - iscsi_iftrans.h (iscsi transport interface);
               - iscsi_proto.h (RFC3720 #defines and types).

               Signed-off-by: Alex Aizman <itn780@yahoo.com>
               Signed-off-by: Dmitry Yusupov <dmitry_yus@yahoo.com>