[@Ellri] I started implementing a tag editor on the admin panel.

To test it, so far I extracted and added time-period tags:

[img]https://dl.dropboxusercontent.com/spa/quq37nq1583x0lf/l2duesn6.png[/img]

I'll add some of the thematic ones soon.

I should probably bump the max tag count up from 5 to 6 once I add more.