Split @protocol into @protocol and @for and add __impl__(:for)
Merge pull request #1481 from meh/protocol

Split @protocol into @protocol and @for and add __impl__(:for)
Do not show internal compiler output in stacktraces
Improve inspect for functions
Fix the build
Fixed typos in Mix.Tasks.Test docs
Merge pull request #1485 from jwarwick/test_typo

Fixed typos in Mix.Tasks.Test docs
Warn for unmatched docs
Give more information on invalid versions
Rename Protocol.UndefinedError keys
binary_size => byte_size
Get rid of unmatched docs warnings
Clean up IEx helpers to not contain spurious functions
Update CHANGELOG