add description parameter to OPT__VERBOSE

Allows better help text to be defined than "be verbose".  Also make use
of the macro in places that already had a different description.  No
object code changes intended.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

test-parse-options.c

@@ -66,7 +66,7 @@ int main(int argc, const char **argv)
 		  "negative ambiguity", PARSE_OPT_NOARG | PARSE_OPT_NONEG },
 		OPT_GROUP("Standard options"),
 		OPT__ABBREV(&abbrev),
-		OPT__VERBOSE(&verbose),
+		OPT__VERBOSE(&verbose, "be verbose"),
 		OPT__DRY_RUN(&dry_run),
 		OPT__QUIET(&quiet),
 		OPT_END(),