Add recent directories to save dialog

[chowbok]

The official version of mcomix offers recent directories in the save file browser. Could this be added to mcomix3?

Alternatively, perhaps it could default to the last directory files were saved in?

[multiSnow]

If you mean the 'Recent' location above 'Home' and 'Trash' in the left column of file chooser dialog, it just disappeared in gtk3 if the action of Gtk.FileChooserDialog is Gtk.FileChooserAction.SAVE.

I have even tried the demo code but still not find the 'Recent' location, different from the screenshot.

It seems to be so-designed.