test: use numstat instead of diffstat in funny-names test

test: use numstat instead of diffstat in funny-names test

This test script checks that git's plumbing commands quote filenames
with special characters like space, tab, and double-quote
appropriately in their input and output.

Since commit v1.7.9.2~13 (Use correct grammar in diffstat summary
line, 2012-02-01), the final "1 file changed, 1 insertion(+)" line
from diffstats is translatable, meaning tests that rely on exact "git
apply --stat" output have to be skipped when git is not configured to
produce output in the C locale (for example, when GETTEXT_POISON is
enabled).  So:

 - Tweak the three "git apply --stat" tests that check "git apply"'s
   input parsing to use --numstat instead.

   --numstat output is more reliable, does not vary with locale, and
   is itself easier to parse.  These tests are mainly about how "git
   apply" parses its input so this should not result in much loss of
   coverage.

 - Add a new "apply --stat" test to check the quoting in --stat output
   format.

This wins back a little of the test coverage lost with the patch
"test: use test_i18ncmp to check --stat output" when GETTEXT_POISON is
enabled.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>