Fix `String.ljust/2,3` and `String.rjust/2,3` functions
Move string justification defaults to the function heads
No need for `do_` prefix in `String.do_justify/4`
Merge pull request #2856 from lexmag/fix-string-justify

Improve string justification functions
Fix type of Inspect.Opts limit
Correct Enum.take, Enum.take_every, Stream.take, Stream.take_every to accept proper nth/count values
Merge pull request #2859 from eksperimental/take

Correct Enum.take, Enum.take_every, Stream.take, Stream.take_every
Merge pull request #2858 from mururu/fix-limit-type

Fix type of Inspect.Opts limit
fix documentation of String module
fix spec and add more test for String.duplicate/2
Merge pull request #2861 from jw2013/string

Improve String module
Merge branch 'master' of https://github.com/elixir-lang/elixir