Automatically update gallery when a new image is added

[wdsrocha]

Change behavior from manually running make_gallery.py to automatically listen when a new image is added to wallpaper directory. This change must guarantee total synchronization between images, thumbnails and README file.

Probably what will be used to solve this issue: https://github.com/rvoicilas/inotify-tools/wiki

[wdsrocha]

Maybe this should do the job.