Add pwd and cd helpers to IEx
Improve docs for Dict
Fix the build
Add cover support to mix test
Do not run cover tests before R16
Improve error message on unclosed interpolation/string, closes #794
Support --help and -h in elixir and iex, closes #854
Fail if an application can't be started, closes #869
Add Path.t (for input types) and Path.r (for output), closes #873
Revert "IEx autocompletion should show all exported functions, not only documented ones"

This reverts commit 3ffc5e9e8497cac9312dc02dbb8f763b9ee9edf7.

Closes #879.