In https://github.com/adobe/brackets/blob/randy/issue-7020/src/editor/EditorStatusBar.js#L134 we make the value be between 1 and 10 for both preferences. Should we make 10 the max here too? And should we fix the min there so that it can be 0 for space units? Once we do that, the min and max values should be exported constants so that we can use them in EditorStatusBar.