Add these missing items to release notes

[ericfranz]

• grafana config: allow changing the cluster config name when the cluster in OOD differs from the cluster in Grafana #639
• Native VNC connection tab for OOD can be enabled for sites external to OSC #625
• Added Sinatra gems into ondemand-gems for other apps to use 579
• Specify the default login host in the cluster config #508
• Control nginx max upload size by setting byte size in nginx_stage.yml using configuration option nginx_file_upload_max and the files app will now respect this #502
• Streamlined Copy and Paste in NoVNC for Chrome #537

[ericfranz]

I'd also add a section:

• Drop IE support

I will be adding a page in the Requirements section for Browser requirements. I think that we should say if IE support is required and you have time to contribute to development and support of IE in OnDemand, reach out to us.