REORG: include: move stream_interface.h to haproxy/stream_interface{,-t}.h

Almost no changes, removed stdlib and added buf-t and connection-t to
the types to avoid a warning.
diff --git a/include/types/stream.h b/include/types/stream.h
index 0c1475f..a67d192 100644
--- a/include/types/stream.h
+++ b/include/types/stream.h
@@ -34,6 +34,7 @@
 #include <haproxy/list-t.h>
 #include <haproxy/obj_type-t.h>
 #include <haproxy/session-t.h>
+#include <haproxy/stream_interface-t.h>
 #include <haproxy/vars-t.h>
 
 #include <types/channel.h>
@@ -42,7 +43,6 @@
 #include <types/proxy.h>
 #include <types/queue.h>
 #include <types/server.h>
-#include <types/stream_interface.h>
 #include <haproxy/task-t.h>
 #include <haproxy/stick_table-t.h>