Change mDNS naming policy

[Hubert Banaszewski]

mDNS naming changes:

• service type: _unlimited._tcp into _gu_hub._tcp and _gu_provider respectively,
• service name: gu-hub and gu-provider into name of the host

Progress:

• hub and provider publish according to the new policy
• lan list works with properly after the change (also waiting time for responses is reduced from 1000 to 100 ms)
• auto connecting works after the modification