CIDER 2.0: The Plan

I'm thinking of cutting one final CIDER 1.x release soon, before #3352 is finished, and then prepare for a CIDER 2.0 release. Why so?

- it feels like a good time to drop Clojure 1.8 support, given that almost no one uses it
- we'll also be able to simplify the code related to clojure.spec
- a new major version will allows to tweak some defaults, like the ones we've recently discussed with @yuhan0
- might be a good opportunity to make bigger changes to the connection management

Ideas/concerns are welcome!

Start by reading the discussion in this issue and the referenced #3352. Review the proposed Clojure 1.8 support removal, clojure.spec simplification, default changes, and connection-management changes. Done means reaching agreement on a concrete CIDER 2.0 plan and release scope.

Written by the indexing model from the issue text.