Tidy up display of editions

* Use #X notation for brevity.
* Match colour of slug link
Make dates user friendly

* Use human readable date formats that match our style guide
* Shorten columns to show only the date, put provide the full date as a
title attribute if the user needs to check
Remove action columns and icons

The edit view can be consistently reached via the link on the
publication title. The preview can be reached via the link on the
publication slug.

* Remove the 2-4 columns for edit, preview, locked view
* Keep an actions column when a new edition can be created from a
published or archived edition. Shorten button text.