Add Enable Cookies Jar File, enable cookie session  and Update Readme

Was adding new functions for support cookies jar and cookie file, 
and update ( add ) readme file with example usage of Cookies Jar Function.
Cookies Jar File Maybe easier and my project need this.

```php
setCookieFile($cookiefile, $time=86400) 
```

 + added enable cookie session.
```php
session($on=true) 
```

is this acceptable?