IEx helpers r and c can handle erlang sources
Merge pull request #1552 from ericmj/iex-erlang-helpers

IEx helpers r and c can handle erlang sources
Fix for #1555
Fix regression on do/end blocks, closes #1551
Merge pull request #1556 from derekmcloughlin/issue-1555

Fix for #1555
Remove deprecated code
Reduce the ammount of module binaries being passing around
Add regex pattern support to String.replace
Merge pull request #1557 from meh/string-replace

Add regex pattern support to String.replace
Improve Enum.shuffle and String.replace docs
List.replace_at
Merge pull request #1558 from sasa1977/list_replace_at

List.replace_at
Fix a bug in insert_at adding items to the wrong location with negative indexes
Add Enum.reduce/2 that sets initial value of acc to the first element of collection

Signed-off-by: José Valim <jose.valim@plataformatec.com.br>

Conflicts:
	lib/elixir/lib/enum.ex
Refactor Enum.min/1 and Enum.max/1
Deprecate Enum.min/2 and Enum.max/2 in favor of Enum.min_by/2 and Enum.max_by/2
Update CHANGELOG
Make System.get_env/0 behave sanely.