Live Preview

[I-Valchev]

The reviewed preview should have two options:

• When the Preview is opened in a new tab (as is right now), make sure it keeps updating on every change. We already detect change Warn editors for unsaved changes to content #2309, we have to make sure it gets updated. With JavaScript from the Edit page feeding into the Preview tab.
• Live preview on the edit page itself, side by side with the editor. Similar solution to the first one!