Keep picking up icons as resources

We may need to revisit this at some point. For now,
keep the mechanism in place.

This is a partial revert of 806c659efe.

gtk/gen-gtk-gresources-xml.py

@@ -61,6 +61,13 @@ for f in get_files('ui', '.ui'):
 
 xml += '\n'
 
+for s in ['16x16', '24x24', '32x32', '48x48']:
+  for c in ['actions', 'status']:
+    icons_dir = 'icons/{0}/{1}'.format(s,c)
+    if os.path.exists(os.path.join(srcdir,icons_dir)):
+      for f in get_files(icons_dir, '.png'):
+        xml += '    <file>icons/{0}/{1}/{2}</file>\n'.format(s,c,f)
+
 for f in get_files('inspector', '.ui'):
   xml += '    <file preprocess=\'xml-stripblanks\'>inspector/{0}</file>\n'.format(f)