updated changelog with #641 change

CHANGELOG.md

@@ -21,6 +21,7 @@
 
 **Changes**
 - [Issue #536](https://github.com/grafana/grafana/issues/536). Graphite: Use unix epoch for Graphite from/to for absolute time ranges
+- [Issue #641](https://github.com/grafana/grafana/issues/536). General: Dashboard save temp copy feature settings moved from dashboard to config.js, default is enabled, and ttl to 30 days
 
 **Fixes**
 - [Issue #545](https://github.com/grafana/grafana/issues/545). Chart: Fix formatting negative values (axis formats, legend values)