[devel] Removed PNG_CONST from all "PNG_CONST PNG_CHNK" declarations

to avoid compiler complaints about doubly declaring things "const".
diff --git a/CHANGES b/CHANGES
index 5e2cd39..7f8ddbc 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2239,6 +2239,8 @@
 version 1.4.0beta81 [September 20, 2009]
   Eliminated unused PNG_FLAG_FREE_* defines from pngpriv.h
   Expanded TAB characters in pngrtran.c
+  Removed PNG_CONST from all "PNG_CONST PNG_CHNK" declarations to avoid
+    compiler complaints about doubly declaring things "const".
 
 version 1.4.0betaN [future]
   Build shared libraries with -lz and sometimes -lm.