Use full (advanced) text editor in quick reply box

The quick reply box should have the full editor capabilities. There's absolutely no reason for it to have only a subset of features. Especially since the syntax highlighting is not available in the quick reply, which we almost always have to use.

Currently, I have to interrupt my reply as soon as I need to insert code, click on the Advanced Editor, answer "Leave this page" in the popup (which is scary, btw), wait for the page to load, then keep typing. Only now, I can't see the complete thread, so I'm stuck if I need to reference information from other messages in the thread.