eth: calculate the correct TD, only update if better

eth, ethdb: fix a data race during startup/shutdown

Core uint64 ts

added net.version

Adjust .mailmap

web3 update

ParamsToAddress no longer aborts the process, it now returns an error
instead so that the caller can handle the error properly.

all: update license information and godoc comments

This version is less clever. All names are listed in a single file,
AUTHORS. All source files have the same header. This is an improvement
over the previous version, which attempted to list copyright holders in
each source file.

ParamsToAddress no longer aborts the process, it now returns an error
instead so that the caller can handle the error properly.

cmd,eth,rpc,tests: default coinbase

Rebase registrar

registry initialisers now return the txhash which caller can use to retrieve receipt