Update service statistics

Update service statistics

Instead of collecting statistics on interface name base and storing it
local in counter.c, update the Service object.

counter.c maps interface names to Service objects.
The assumption is made that there is a 1:1 mapping between Service objects
and interface name.

A Counter object will only show Service object statistics for services in
the ready state. There is no interface (yet) for retrieving information on
Service objects in idle/failure/configuration/.. state.