Use line from :keep when there is a :file meta in definitions
Emit :file attribute on all nodes instead of a select few
Make elixir_errors API more strict and consider :file in meta
Do not call handle_file_warning directly
Do not allow deps names on mix deps.get

Closes #2507.
Use short filenames to handle spaces in path to bin\mix
Merge pull request #2508 from chyndman/mix-bat-short-names

Use short filenames to handle spaces in path to bin\mix