New features:

Responsive Design (for Basic and EPUB licenses).

Color buttons are back, per user request.

It's now possible to hide/show most toolbars.

Other important changes:

Drag-and-drop of an image from Finder/File Explorer now links to the image instead of creating a data URL.

"Restore previous session" feature dropped.

Major bug fixes:

Fix for crasher in OS X colorpicker.

Fix for broken shortcuts.

Fix for undesired markup appearing in liveview (source part).

Fix for broken command line handler.

Fix for broken spellchecker dialog.

Because of a change in Mozilla Gecko, a CR at the end of for instance a H1 was not creating a P any more; this is fixed.