New "Set as favorite" plugin, feedback request

[Alessio 'molok' Bolognino <themolok gmail com>]

Hi guys,
I wrote a new plugin for EOG: "Set as favorite"; it's a plugin to
set/toggle the favorite emblem on pictures from EOG, when it's set it
shows a little heart ( ❤ ) in the statusbar. There is a feature request
about this in the bugtracker [1], even though it has not received much
attention.

My C/GTK is a bit rusty, so I'd like to hear feedback on the code.
Moreover, I wrote it to work with EOG 2.32.0, which is the version I
have installed on this machine, I just read that the plugin API is going
to change, I am willing to port it to EOG 2.9X.

What would be the path to follow to include my plugin in EOG?

The code is located here [2]

The FR from the bugtracker:
«I'm a semi-professional photographer who (generally) happily uses Eye
of GNOME to go through collections of photos I've taken. 

My workflow mainly consists of viewing large numbers of often duplicate
shots that vary only slightly. These slight differences, however,
determine which ones I end up salvaging and which ones I ignore. 

It would be great to somehow "star" good shots that I want to mark for
later review, much like Gmail's star feature or Nautilus emblems that
allow users to sort items based on arbitrary user-set values»

[1] https://bugzilla.gnome.org/show_bug.cgi?id=589198
[2] https://github.com/molok/eog-set-as-favorite-plugin
-- 
Alessio (molok) Bolognino