As x264 can't get correct version information in configure, L-SMASH also can't.

・Correct (using :revision)

```bash
$ boxdumper -v

L-SMASH isom/mov structual analyzer rev     898  61fcd5e
Built on Mar 26 2014 15:29:19
Copyright (C) 2010-2014 L-SMASH project
```

・Incorrect (using :tag)

```bash
$ boxdumper -v

L-SMASH isom/mov structual analyzer rev       1  61fcd5e
Built on Mar 26 2014 15:31:59
Copyright (C) 2010-2014 L-SMASH project
```

・Incorrect (using tarball)

```bash
$ boxdumper -v

L-SMASH isom/mov structual analyzer rev       0
Built on Mar 26 2014 15:28:39
Copyright (C) 2010-2014 L-SMASH project
```