[META] 2.0.0 stable blocker bugs

Problem/Motivation

We are using this (drupal.org) issue queue to track "stable blocker" issues ahead of the 2.0.0 release. However, we are also using GitHub to track some bug reports that are not represented in this issue queue. I don't want those to be forgotten in the lead up to the 2.0.0 release.

Proposed resolution

Rather than moving/copying the GitHub issues over to this queue, I am opening this as a meta tracking issue with a "stable blocker" tag so we don't forget them.

We can use this to maintain a list of links to GitHub issues that we deem important enough to block the stable release.

Remaining tasks

1. Triage GitHub issues and make a list of the important ones here.
2. Fix all the bugs!