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-archive.c

@@ -13,7 +13,7 @@
 #include "attr.h"
 
 static const char archive_usage[] = \
-"git-archive --format=<fmt> [--prefix=<prefix>/] [--verbose] [<extra>] <tree-ish> [path...]";
+"git archive --format=<fmt> [--prefix=<prefix>/] [--verbose] [<extra>] <tree-ish> [path...]";
 
 #define USES_ZLIB_COMPRESSION 1