Merge branch 'tb/check-crlf-for-safe-crlf'

The "safe crlf" check incorrectly triggered for contents that does
not use CRLF as line endings, which has been corrected.

* tb/check-crlf-for-safe-crlf:
t0027: Adapt the new MIX tests to Windows
convert: tighten the safe autocrlf handling