Teach --recursive to submodule sync

diff --git a/RelNotes b/RelNotes
index d04f1ae46c0477ecd97306db5d76d8f3b60b9415..2484b38bbbae654684f65a874653487439f0df2f 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/1.7.11.6.txt
\ No newline at end of file
+Documentation/RelNotes/1.8.0.txt
\ No newline at end of file