test-lib: introduce the '-V' short option for '--verbose-log'

'--verbose-log' is one of the most useful and thus most frequently
used test options, but due to its length it's a pain to type on the
command line.

Let's introduce the corresponding short option '-V' to save some
keystrokes.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/README

@@ -154,6 +154,7 @@ appropriately before running "make".
 	As the names depend on the tests' file names, it is safe to
 	run the tests with this option in parallel.
 
+-V::
 --verbose-log::
 	Write verbose output to the same logfile as `--tee`, but do
 	_not_ write it to stdout. Unlike `--tee --verbose`, this option

t/test-lib.sh

@@ -67,7 +67,7 @@ case "$GIT_TEST_TEE_STARTED, $* " in
 done,*)
 	# do not redirect again
 	;;
-*' --tee '*|*' --va'*|*' --verbose-log '*)
+*' --tee '*|*' --va'*|*' -V '*|*' --verbose-log '*)
 	mkdir -p "$TEST_OUTPUT_DIRECTORY/test-results"
 	BASE="$TEST_OUTPUT_DIRECTORY/test-results/$(basename "$0" .sh)"
 
@@ -285,7 +285,7 @@ do
 			echo >&2 "warning: ignoring -x; '$0' is untraceable without BASH_XTRACEFD"
 		fi
 		shift ;;
-	--verbose-log)
+	-V|--verbose-log)
 		verbose_log=t
 		shift ;;
 	*)