new ARGBEGIN & usage() function

arg.h

@@ -1,31 +0,0 @@
-extern char *argv0;
-
-#define USED(x) ((void)(x))
-
-#define ARGBEGIN	for (argv0 = *argv, argv++, argc--;\
-					argv[0] && argv[0][1]\
-					&& argv[0][0] == '-';\
-					argc--, argv++) {\
-				char _argc;\
-				char **_argv;\
-				if (argv[0][1] == '-' && argv[0][2] == '\0') {\
-					argv++;\
-					argc--;\
-					break;\
-				}\
-				for (argv[0]++, _argv = argv; argv[0][0];\
-						argv[0]++) {\
-					if (_argv != argv)\
-						break;\
-					_argc = argv[0][0];\
-					switch (_argc)
-
-#define ARGEND			}\
-				USED(_argc);\
-			}\
-			USED(argv);\
-			USED(argc);
-
-#define EARGF(x)	((argv[1] == NULL)? ((x), abort(), (char *)0) :\
-			(argc--, argv++, argv[0]))
-