Soft deprecate Mix.Generator.from_file/1
Remove --gen-debug option
Ensure we show a consistent error when we cannot evaluate .iex.exs
Document the role of MIX_HOME more explicitly
Ensure we can only use variables and `\\` as arguments of bodyless clause, closes #2374
Merge pull request #2457 from mururu/args-for-bodyless

Ensure we can only use variables and `\\` as arguments of bodyless clause
Enum.join/2 and Enum.map_join/3 now uses iolists
Add MIX_ARCHIVES env variable