use modern (2018) pattern for modules

src/browser/header/mod.rs

@@ -1,36 +0,0 @@
-mod subject;
-mod tray;
-
-use subject::Subject;
-use tray::Tray;
-
-use gtk::{glib::GString, HeaderBar};
-
-pub struct Header {
-    widget: HeaderBar,
-    subject: Subject,
-}
-
-impl Header {
-    // Construct
-    pub fn new() -> Self {
-        let tray = Tray::new();
-        let subject = Subject::new();
-
-        let widget = HeaderBar::builder().build();
-        widget.pack_start(tray.widget());
-        widget.set_title_widget(Some(subject.widget()));
-
-        Self { widget, subject }
-    }
-
-    // Actions
-    pub fn update(&self, title: Option<GString>, description: Option<GString>) {
-        self.subject.update(title, description);
-    }
-
-    // Getters
-    pub fn widget(&self) -> &HeaderBar {
-        &self.widget
-    }
-}