Service class checks

//service class checks are  still configured in .htconfig.php: A shiny UI will come later
$a->config['system']['default_service_class']='standard';  // this is the default service class that is attached to every new account
//example configuration for standard service class
$a->config['service_class']['standard'] = 
array('photo_upload_limit'=>20000000, // total photo storage limit per channel (here 20MB)
        'total_identities' =>5, // number of channels an account can create 
        'total_items' =>2000, // number of top level posts a channel can create. Applies only to top level posts of the  channel user, other posts and comments are unaffected
        'total_pages' =>10, // number of pages a channel can create
        'total_channels' =>500, // number of channels the user can add, other users can still add this channel, even if the limit is reached
        'attach_upload_limit' =>20000000); // total attachment storage limit per channel (here 20MB)