Merge branch 'sb/dashless'

* sb/dashless:
  Make usage strings dash-less
  t/: Use "test_must_fail git" instead of "! git"
  t/test-lib.sh: exit with small negagive int is ok with test_must_fail

Conflicts:
	builtin-blame.c
	builtin-mailinfo.c
	builtin-mailsplit.c
	builtin-shortlog.c
	git-am.sh
	t/t4150-am.sh
	t/t4200-rerere.sh

builtin-rev-list.c

@@ -17,7 +17,7 @@
 #define COUNTED		(1u<<16)
 
 static const char rev_list_usage[] =
-"git-rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
+"git rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
 "  limiting output:\n"
 "    --max-count=nr\n"
 "    --max-age=epoch\n"