Add function(Module.fun/arity) and function(fun/arity) syntax

These are equivalent to function(Module, :fun, arity) and function(:fun, arity) constructs, respectively
Merge pull request #665 from yrashk/function-reference-syntax

Add function(Module.fun/arity) and function(fun/arity) syntax
--debug-info is now true by default
Update CHANGELOG
Deprecated `assert left in right` in favor of `assert left inlist right`, closes #662
Make CHANGELOG more consistent
Support `\xXX` and `\x{HEX}` escape sequences in strings and char lists

It implements the same behaviour as seen in regexes. Closes #661.
Ensure debug_info is actually set to true
Make ExUnit exit happen in two steps.

This allows developers to hook custom mechanisms
after the tests are run but before the system halts.
Do not add lines to __info__ function
Ensure IEx boots fast and with Elixir available, closes #673
elixir_code_server should not trap exits and should not log on terminate
Merge pull request #675 from yrashk/code-server-terminate

elixir_code_server should not trap exits and should not log on terminate
Change function type specification syntax (WIP)

Signed-off-by: José Valim <jose.valim@plataformatec.com.br>
More work on improved typespec syntax
Support -> inside parenthesis

This is consistent with the fact that do...end
is a direct translation to do: (...).
Ensure parenthesis are allowed in call args
Change fun(... :: signature) specification format to (... -> signature)
Add a more explicit syntax for ((...) -> ...): (fun(...) -> ...)
Merge pull request #678 from yrashk/jv-new-spec

Change fun(... :: signature) specification format to (... -> signature)