Mark .bat files as requiring CR/LF endings

Mark .bat files as requiring CR/LF endings

Just like the natural line ending for Unix shell scripts consist of a
single Line Feed, the natural line ending for (DOS) Batch scripts
consists of a Carriage Return followed by a Line Feed.

It seems that both Unix shell script interpreters and the interpreter
for Batch scripts (`cmd.exe`) are keen on seeing the "right" line
endings.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>