Add short tickets php api examples in a single file

[FernandoOjeda]

Add short tickets php api examples in a single file:

1. Get tickets using an objectFilter https://sldn.softlayer.com/php/ticket_filter/.
2. GetTicketsClosedSinceDate.php https://sldn.softlayer.com/php/GetTicketsClosedSinceDate.php/.
3. CreateAdministrativeTicket.php https://sldn.softlayer.com/php/CreateAdministrativeTicket.php/.
4. CreateStandardTicket.php https://sldn.softlayer.com/php/CreateStandardTicket.php/.