Use the build system “meson” (close #32)

Replace the build system “setuptools” with “meson”.

src/albumheaderbar.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+
+
+import gi
+gi.require_version('Gtk', '3.0')
+
+from gi.repository import Gtk, GObject
+
+
+
+
+@Gtk.Template(resource_path='/xyz/suruatoel/mcg/ui/album-headerbar.ui')
+class AlbumHeaderbar(Gtk.HeaderBar):
+    __gtype_name__ = 'McgAlbumHeaderbar'
+    __gsignals__ = {
+        'close': (GObject.SIGNAL_RUN_FIRST, None, ())
+    }
+
+    # Widgets
+    standalone_title = Gtk.Template.Child()
+    standalone_artist = Gtk.Template.Child()
+
+
+    def __init__(self):
+        super().__init__()
+
+
+    @Gtk.Template.Callback()
+    def on_close_clicked(self, widget):
+        self.emit('close')
+
+
+    def set_album(self, album):
+        self.standalone_title.set_text(album.get_title())
+        self.standalone_artist.set_text(", ".join(album.get_albumartists()))