Toggle between proportional
and non-proportional view scaling
To non-proportionally scale an orthographic view, you must now use View > Set Non Proportional View, which replaces the Non-Proportional option that was previously hidden within the View > World Move Camera > Dolly tool.
A new tool, View > Toggle Non Proportional View, allows you to toggle the view of the current window between proportional and non-proportional scaling. This only has an effect if you have first non-proportionally scaled the view. No other aspects of the camera view are changed when using this tool.
A Non Proportional View
icon 
is displayed in the lower
left hand corner of the window when the view is non proportional.
icon in the Viewing
Panel to non-proportionally scale a view in the Perspective window.
This icon only appears after you turn off the Perspective option.
When saving the file, both the proportional and non-proportional views are saved, and the toggle will still operate properly after the file is re-opened. This is also the case when saving only the window layout with Layouts > User windows > Save Current Layout and retrieving it with Layouts > User windows > Retrieve Layout.
Both tools are available as hotkeys from the Hotkey Editor.