Remove redzone support.

This resolves #369.
diff --git a/INSTALL b/INSTALL
index 4f57b36..e4f7bbd 100644
--- a/INSTALL
+++ b/INSTALL
@@ -165,9 +165,8 @@
     normal jemalloc operation.
 
 --disable-fill
-    Disable support for junk/zero filling of memory and redzones.  See the
-    "opt.junk", "opt.zero", and "opt.redzone" option documentation for usage
-    details.
+    Disable support for junk/zero filling of memory.  See the "opt.junk" and
+    "opt.zero" option documentation for usage details.
 
 --disable-zone-allocator
     Disable zone allocator for Darwin.  This means jemalloc won't be hooked as