To manage services (available features and their cost), use the command core/update_billing_service:

svc=account/update_billing_service&params={"itemId":<long>,
					   "name":<text>,
					   "type":<ubyte>,	
					   "intervalType":<ubyte>,
					   "costTable":<text>,
					   "description":<text>}

Service types:

• 1 – on demand (for example, SMS). IntervalType defines frequency of service usage counter reset.
• 2 – periodic services, payments for them must be performed in specified time interval.

Interval types:

• 0 – never;
• 1 – hourly;
• 2 – daily;
• 3 – weekly;
• 4 – monthly.

{}	/* empty object if execution successful, if not - error code */