Upgraded hashids.php and removed version specific code from start.php

I upgraded `hashids.php` to version `0.2.1`.

Went in and changed `start.php` to remove version specific code as it is no longer needed.

Removed: `hashids.php-5-3.php`

Tested on PHP version `5.3.21` and `5.4.11` using the following code:

```php
$hash = $hasher->encrypt(1, 2, 3, 4);
echo "<pre>" . print_r($hash, true) . "</pre>";
echo "<pre>" . print_r($hasher->decrypt($hash), true) . "</pre>";
```