Make Mix CLI support --help, -h and -help, fixes #843
Use fn clause matching

This does not perform downcasing and thus makes BASIC refugees
unhappy, but @yrashk suggests we can live with that.
Merge pull request #844 from michaelklishin/issue843

Make Mix support --help, -h and -help
Disable native compilation when on_load attributes is present

This is a work around an Erlang bug, see #845 for more information.
Closes #845.
Add metadata support to ExUnit

Defining setup/teardown/test explicitly is now deprecated.
They should now be defined via their respective macros:

    def setup do
      ...
    end

Now becomes:

    setup do
      ...
    end

When defined using the new format, setup callbacks can
return metadata:

    setup do
      [do_this: :do_that]
    end

And now the test macro can access this metadata:

    test "check metadata", data do
      assert data[:do_this] == :do_that
    end
correct apply/3 example
Merge pull request #847 from jeremyjh/apply-doc-fix

correct apply/3 example
Add support to case templates
ExUnit callbacks must return :ok or { :ok, data }
Deprecate ExUnit.after_spawn callbacks
Release v0.8.1
Add more info to release process
Fix typo in RELEASE.md
ANSIfy ExUnit formatter
Print a warning if ExUnit user config contains an invalid value, and assume an empty user config

This change prevents ExUnit from crashing when trying to merge invalid options and warns the user about the problem early on
Add elapsed times to ExUnit runs
Update CHANGELOG
Use latest ExDoc
Fix bug in Path.expand
Better error reporting for invalid bit string comprehension generators