Improve Enumerable count/member? docs
Change the Path module to work only with char_data and always return binaries
Convert File and IO to char data, use +fnu flag by default
Provide List.from_char_data! and String.from_char_data!
Rename iolist_* to iodata_*
Properly @spec functions in Path
Typespec and allow char data in File functions
Properly indent chunks in System module
Reject __struct__ field on struct/2
Properly format and indent test output
Allow overriding of undefined dependency SCM

This allows a developer to override an unrecognized SCM without Mix
raising.
Merge pull request #2181 from ericmj/override-undef-scm

Allow overriding of undefined dependency SCM
Improve noscm error message
Release v0.13.0
Start v0.13.1-dev
use 0.13 exunit exception in doctest
Merge branch 'jv-char-data'

Conflicts:
	lib/eex/lib/eex/tokenizer.ex
	lib/elixir/lib/file.ex
	lib/elixir/lib/kernel.ex
	lib/elixir/lib/record/extractor.ex
	lib/elixir/lib/string.ex
	lib/ex_unit/lib/ex_unit/doc_test.ex
	lib/mix/lib/mix/archive.ex
	lib/mix/lib/mix/dep/fetcher.ex
	lib/mix/lib/mix/dep/umbrella.ex
Update CHANGELOG
Merge pull request #1984 from pminten/enumerable-count-doc-improvement

Improve Enumerable count/member? docs
Remove some deprecated functions and add missing warnings