allow for tickets to be opened by support on behalf of user through API call

Sample JSON array:

$data = array(
    'name'      =>      'slartibardfast',
    'email'     =>      'me@myemail.com',
    'subject'   =>      'Test API message',
    'message'   =>      'This is a test of the osTicket extended API',
    'ip'        =>      'a.b.c.d',
    'attachments' => array() ,
    'source'		=>	'other',
    'asStaff'		=>	1,
    'topicId'		=>	1
);

Source should be one of "email", "phone", "other"
asStaff can be either id# of the Staff member, or staff name (creation of new Staff allows both options already... 1 is just easier)
topicId is required by the validation, represents a topic# reference for user.