Dedicated inspect implementation for regexes. Fix #2250

We no longer share the implementation with BitString because regex
literals have slightly different escaping rules
Change help heading on mix
Ensure doctests failures are properly tested
Remove unused reduce/3 from map
Merge pull request #2320 from alco/regex-literal

Draft implementation of custom inspect algorithm for regexes
Update CHANGELOG
Ensure config/config.exs is really persisted
Do not allow keyword on containers without pos args
Remove :docs and :moduledoc clauses from the __info__ function

Instead, we keep the docs in a custom chunk within the .beam file;
this will allow us to lazily load them
Add Code.get_docs/2 function
Add version tag to Elixir’s beam chunk

This will allow us to change the layout of the chunk in the future
Preserve docs chunk during protocol consolidation
Update tests that need to read module docs to write BEAM code to disk
Change Stream's struct to just %Stream{}
Merge pull request #2332 from devinus/stream-struct

Change Stream's struct to just %Stream{}
Release v0.13.3
Merge pull request #2326 from alco/docs-beam-chunks

Docs beam chunks
Start v0.14.0-dev
Fix formatting and proof-read GenEvent docs
Merge pull request #2333 from alco/genevent-doc

Fix formatting and proof-read GenEvent docs