* fix(dns): decode up to four answer records
A single DNS question can return multiple answer records. Use an answer
decode limit of four in Client.StartResolve and add a regression test
covering a single-question response with multiple A records.
* fix(dns): add MaxResponseAnswers to ResolveConfig
This allows callers to explicitly declare the maximum number of answer
records to retain, removing the hardcoded limit in Client.StartResolve.
xnet.StackAsync is updated to set this limit to match the length of its
lookup-result buffer. This maintains the zero-allocation design while
fixing the issue where multiple A records were ignored.
* add ipv6 to xnet.StackAsync
* dns improvements
* improve DNS workings of StackAsync
* add tentative ICMPv6
* work on prefixes and fix some small bugs, plan UDP/TCP6
* fix bugs in StackAsync and ipv4.Prefix.Contains
* update arpsubtable
* completely remove legacy internet.StackIP for StackIPv4/v6
* ipv4/ipv6 tcp/udp
* add TCP6/UDP6 dialing APIs
* add xnet.Stack6 interface
* more ipv6 integration into StackAsync; various tweaks to lneto and documentation+TODOs
* add stack6 tests
* replace netip.Prefix with ipv4.Prefix where it makes sense
* add mdns
* define mdns.Client
* fix some mdns stuff
* refine dns package for use with mdns
* remove Querier and Responder and replace with Client
* add record setting methods on dns.record to reuse record buffer
* protect against unbounded client answer growth
* round off sharp mdns edges; reduce allocs
* add mutlicast to stacks; add xnet tests for mdns
* fix documentation on acceptmulticast field
* mdns working
* pcap: reuse Frame memory
* slog: reduce heap allocations of addresses; also prevent heap alloc of dhcp options in pcap
* dns: heapless improvement; add StackAsync buffer for more heapless operation; start thinking of errors
* errors: begin standardise errors in lneto
* errors: finish standardization of errors
* fix merge issues
* add more lneto errors to rest of package
* format errors.go
Yoshio HANAWA
Pat Whittingslow