Change attribute negation marker from '!' to '-'.

diff --git a/RelNotes b/RelNotes
index d5e055de6f26abba256cf32bed8dfb056bc6b29c..c543b1d1eedf821fe1e8c31d902a719bfc6ffb20 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes-1.5.1.txt
\ No newline at end of file
+Documentation/RelNotes-1.5.2.txt
\ No newline at end of file