v0.4.0

• Add ctxwrap subpackage for attaching context.Context to errors (see README for more on this)
• Add wrap.ErrorWithAttrs function for attaching structured log attributes to errors
• Add wrap.Errorsf function for wrapping multiple errors with a formatted message
• Breaking: Change variadic parameter in wrap.Errors to slice of errors
  • This makes the signature of this function more consistent with the other multi-error-wrapping functions in this package
  • To migrate, replace:

    wrap.Errors("error message", err1, err2)

    ...with:

    wrap.Errors([]error{err1, err2}, "error message")

• Make error unwrapping of plain errors more robust (check for Unwrap() error method instead of just splitting on ": ")