Fixed Changelog typos
Merge pull request #2493 from jwarwick/changelog_typos

Fixed Changelog typos
Fix some sentence tenses in changelog
fix range typo
Merge pull request #2494 from jw2013/typo

fix typo in range moduledoc
Always return ok from tracking functions
Return explicit :ok from more functions
Ensure case wrapper in cond gets the proper line
throws error for missing docs in DocTest

Signed-off-by: José Valim <jose.valim@plataformatec.com.br>
Add test cases for ExUnit.DocTest failures
Fix regex compilation and set ucp flags
Check if ANSI escape codes are enabled on IEx's clear, closes #2441
Fix typo in GenEvent moduledoc
Merge pull request #2495 from thmzlt/patch-1

Fix typo in GenEvent moduledoc
Ensure docs with no function raise warnings
Ensure the message is not ANSI escaped

Closes #2496.
Shell info messages can still be escaped
Rename Mix.Shell.info option :escape => :ansi
Emit warnings for underscored variables appearing twice in a pattern, closes #2480
Use a native splitting on String.split/1 instead of relying on regexes

The new implementation is 20x faster for small strings and about
100x times faster for large ones.