REORG: use the name sock_raw instead of stream_sock

We'll soon have an SSL socket layer, and in order to ease the difference
between the two, we use the name "sock_raw" to designate the one which
directly talks to the sockets without any conversion.
diff --git a/src/stream_interface.c b/src/stream_interface.c
index 543cfee..75a6dc9 100644
--- a/src/stream_interface.c
+++ b/src/stream_interface.c
@@ -28,8 +28,8 @@
 
 #include <proto/buffers.h>
 #include <proto/fd.h>
+#include <proto/sock_raw.h>
 #include <proto/stream_interface.h>
-#include <proto/stream_sock.h>
 #include <proto/task.h>
 
 /* socket operations for embedded tasks */