Add 0.5.1 info

Author: KlausBlum

Release Notes.txt

@@ -1,8 +1,14 @@
 *********************************************
-OOoLilyPond 0.5.0 Release Notes  (March 2017)
+OOoLilyPond 0.5.1 Release Notes  (March 2017)
 *********************************************
 
 
+Changes to OOoLilyPond 0.5.1 since 0.5.0:
+==========================================
+
+* fixed: missing parentheses in source code caused runtime error in LibO 5.3.1.2
+
+
 Changes to OOoLilyPond 0.5.0 since 0.4.0/0.4.1:
 ================================================