small changelog update
Fix for auto refresh not being started after loading dashboard, Fixes #655
Timepicker: Fix for setting custom To date with low refresh interval, Fixes #652
Chart: Possible fix for stuck tooltip (annotation or time series point hover tooltip would not disappear), Fixes #450
General: Fix for refresh icon in IE browsers, Fixes #657
added coveralls badge
Merge branch 'master' of https://github.com/grafana/grafana