Optimize temp_vars lookup
Include description and improve formatting

Switching from `AssertionError` to `ExpectationError` gives us a nicer
error message and allows us to easily include the incorrect result as a
description.

Fixes #1276

Signed-off-by: José Valim <jose.valim@plataformatec.com.br>
Clean up ExUnit tests
^x variables should always refer to the value before the expression

Closes #1307
Fixed some incorrect markdown in binary_to_list/3's documentation.

The docs for binary_to_list/3 weren't monospacing their reference to binary_to_list/1, which resulted in some bad italicization.
Merge pull request #1308 from justinweiss/patch-1

Fixed some incorrect markdown in binary_to_list/3's documentation.
Added functions for changing mode, owner and group to module File
Inline list funcs so we don't pay an extra dispatch cost
Allow types to be given to defrecordp

Part of #1288
Add docs to Mix.Version and make version always the first arg
Do not use Enum on bootstrap
Fix typo (tks @ericmj)
Merge pull request #1300 from jdrexler/issue-1285

Added chgrp!, chown!, and chmod! to module File
Support (x, y) when z, closes #1313
Add tests for nested whens
Update CHANGELOG
Ensure esriptize does not try to read directories
Ensure escript_app doesn't break the app
Improve mix escript_app's documentation
Initial work cleaning up op table