Bug 900763 - "edit conditional breakpoint". r=jlong

This patch updates the Source Editor contextmenu's UX. Prior to the
patch, the menu would show the option "Add conditional breakpoint" even
when there was a conditional breakpoint. Now, that option reads "Edit
conditional breakpoint".

devtools/client/sourceeditor/editor.js

@@ -337,6 +337,8 @@ Editor.prototype = {
         if (typeof popup == "string") {
           popup = el.ownerDocument.getElementById(this.config.contextMenu);
         }
+
+        this.emit("popupOpen",  ev, popup);
         popup.openPopupAtScreen(ev.screenX, ev.screenY, true);
       }, false);