Zeroconf

- Implemented Multicast Response Aggregation (\940) bdraco

Responses are now aggregated when possible per rules in RFC6762
section 6.4

Responses that trigger the protection against against excessive
packet flooding due to software bugs or malicious attack described
in RFC6762 section 6 are delayed instead of discarding as it was
causing responders that implement Passive Observation Of Failures
(POOF) to evict the records.

Probe responses are now always sent immediately as there were cases
where they would fail to be answered in time to defend a name.

- Ensure zeroconf can be loaded when the system disables IPv6 (\933)
che0

- Added support for forward dns compression pointers (\934) bdraco
- Provide sockname when logging a protocol error (\935) bdraco

- Handle duplicate goodbye answers in the same packet (\928) bdraco

Solves an exception being thrown when we tried to remove the known
answer from the cache when the second goodbye answer in the same
packet was processed

Fixed \926

- Skip ipv6 interfaces that return ENODEV (\930) bdraco

- Version number change only with less restrictive directory
permissions

Fixed \923

This release eliminates all threading locks as all non-threadsafe
operations now happen in the event loop.

- Let connection\_lost close the underlying socket (\918) bdraco

The socket was closed during shutdown before asyncio's
connection\_lost handler had a chance to close it which resulted in
a traceback on windows.

Fixed \917

Technically backwards incompatible:

- Removed duplicate unregister\_all\_services code (\910) bdraco

Calling Zeroconf.close from same asyncio event loop zeroconf is
running in will now skip unregister\_all\_services and log a warning
as this a blocking operation and is not async safe and never has
been.

Use AsyncZeroconf instead, or for legacy code call
async\_unregister\_all\_services before Zeroconf.close