Read in text mode in a needed place only

Converting CR+LF to LF in blocking_read() which is a underlying read
function, may affect to the functions which do not perform line-based
operation.

    modified:   funcs.c
    modified:   main.c
    modified:   misc.c
    modified:   os2.c
    modified:   shf.c

os2.c

@@ -191,7 +191,8 @@ void os2_init(int *argcp, const char ***argvp)
 	init_extlibpath();
 	env_slashify();
 
-	setmode(STDIN_FILENO, O_TEXT);
+	if (!isatty(STDIN_FILENO))
+		setmode(STDIN_FILENO, O_BINARY);
 	if (!isatty(STDOUT_FILENO))
 		setmode(STDOUT_FILENO, O_BINARY);
 	if (!isatty(STDERR_FILENO))