Max-width in entry images is achieved through CSS instead of adding a "style" attribute to images.

This is necessary because of commit c7d47a9a7f4a753cf0a2d7243c933be63340a826. Now entry content is sanitized with angularJS $sanitize service, which strips any "style" attributes. The same effect can be achieved with CSS, which is more correct, bypasses angularJS sanitization and is probably faster when saving entries.