mix.ex: example "mix run hello" -> "mix hello"
Merge pull request #2834 from pdericson/mix_docs

mix.ex: example "mix run hello" -> "mix hello"
Properly handle eval_failure warnings, closes #2835
Unify error reporting from EEx, closes #2833
Improve token errors for aliases, closes #2818
Fail to compile try without else/catch/after/rescue, closes #2797
Update release instructions
More updates to instructions