NEW ANSWER
The easiest way to do it is to install thunar
(from the Xubuntu distro --- should be as easy as apt-get install thunar
). The Thunar developers have left the emblems option. Once you have set them with thunar
, they are visible in nautilus
too... so no need to change the default file browser if you do not want.
OLD ANSWER
There is another option, see https://github.com/allefant/Nautilus-Emblems-Menu-Extension/blob/master/nautilus_emblems_menu.py (instruction and plea for help in the same file).
You can drop the file also in .local/share/nautilus-python/extensions directory, no need to go superuser.
Sad, I like emblems. If someone knows how to lobby for that...
(By the way, I tried. I was answered WONTFIX. See https://bugzilla.gnome.org/show_bug.cgi?id=665735 )
You can also add the emblems via command line. To see the emblems a file/dir has associated with it, issue
gvfs-info -a metadata::emblems file_or_dir
To set the emblems cool and default on a file/dir:
gvfs-set-attribute -t stringv file_or_dir metadata::emblems cool default
To clear the emblems on file/dir
gvfs-set-attribute -t unset file_or_dir metadata::emblems
Still looking for a gvfs command to list the available emblems...