Use Mix.Version for dependencies
Require `override: true` option to override a dep
Projects without a mix.exs can't be recursive

Otherwise, recursive_enabled? always returns true, even
when it should be disabled, affecting the output of tasks.

Closes #1374
Minor doc fix
Merge pull request #1376 from ericmj/mix-deps-version

Use Mix.Version for dependencies
Replace ?is_new_atom macro by ?is_atom_start
inspect_kw no longer is
Add Stream.seq() for generating potentially infinite streams of values
Ensure Stream.take/2 halts execution
Refactor IEx.Options and raise on bad key
Merge pull request #1389 from alco/iex-options-fix

Refactor IEx.Options and raise on bad key
Small refactoring on IEx.Options
Add Stream.iterate
Add Stream.repeatedly
Fixed typos in IEx.Options docs
Fixed doc typos in the IEx module
Fixed doc typos in IEx.Helpers
Merge pull request #1391 from jwarwick/iex_docs

Fixed doc typos in IEx, IEx.Options and IEx.Helpers
Merge pull request #1390 from pragdave/iterate

Iterate
Rename --docs tests file to docs_test.exs