* begin adding icmp client
* rely on anon structs
* add tests
* tests passing
* icmp fleshed out
* rework icmp to include ip addr
* rename StackAsync.Demux/Encapsulate to RecvEthernet and SendEthernet
* remove legacy unreachable TCP tests
* remove uses of deprecated internet.StackNode in preference of lneto.StackNode
* documentation
* rename methods to signal no I/O happening
* Simplified checksum calculation and verification
* Fixed tests
* UDP: using NewBoundedFrame to create a Frame instance limited to the actual frame size.
* Minor: renamed some functions
* Commented and made more readable consecutive SetCRC calls.
* Fixed icmp checksum calculation after rebase
* Replaced NewBoundedFrame with explicit validation
Pat Whittingslow
ddirect