META: Plan for Metatag 7.x-1.5 release

FYI v7.x-1.5-beta1 was released recently: https://www.drupal.org/node/2418557

FYI I think the last issue that needs to be resolved before 1.5 can be released is the upcoming conversion script for Nodewords: #1281138: Upgrade path: Nodewords

(though I might sneak in a few other improvements too)

1.5 is out! https://www.drupal.org/node/2497167

\o/

FYI I wrote up a blog post that gives an overview of highlights from the new release: https://www.mediacurrent.com/blog/introducing-metatag-15

I also have a presentation about it, but a recording was lost during a computer crash; I'll rerecord it soon.