[DiapDealer]

I'm not sure I can put it back. The logic is pretty twisted already. Right now, it passes the highlighted xhtml file as an argument to the external editor (and the filewatcher is started). Unless the external editor in question is PageEdit, in which case the OPF file and the currently highlighted xhtml file are both passed to PageEdit as arguments (and the multiple watchers are set up by parsing the opf). If no xhtml file is highlighted in Book Browser, nothing happens (see message in status bar). It was determined that users who wanted to open a single xhtml file with PageEdit could do so via the right-click "Open With" in Book Browser.

I guess it just doesn't seem that intuitive to me to select an opf file in Book Browser before activating an external xhtml editor. But I'm up for anything if we can figure it out without breaking the current functionality.