script.h: set_vch() should shift a >32 bit value

Source: http://www.viva64.com/en/b/0268/
qt: Remove an obscure option no-one cares about

Remove the "Display addresses" setting checkbox. It doesn't do what
the tooltip says, and seems kind of pointless in any case.

Fixes #4580.
Merge pull request #4610

bdba2dd qt: Remove an obscure option no-one cares about (Wladimir J. van der Laan)
Merge pull request #4602

6fd59ee script.h: set_vch() should shift a >32 bit value (Jeff Garzik)
Add built-in seeds for .onion

This makes it possible for a node with `-onlynet=tor` to bootstrap
itself.

It also adds the base infrastructure for adding IPv6 seed nodes.

Also represent IPv4 fixed seed addresses in 16-byte format.
Implement "getchaintips" RPC command to monitor blockchain forks.

Port over https://github.com/chronokings/huntercoin/pull/19 from
Huntercoin:  This implements a new RPC command "getchaintips" that can be
used to find all currently active chain heads.  This is similar to the
-printblocktree startup option, but it can be used without restarting
just via the RPC interface on a running daemon.
Merge pull request #4536

b33bd7a Implement "getchaintips" RPC command to monitor blockchain forks. (Daniel Kraft)
doc: Add new DNSseed policy
Merge pull request #4566

0a0878d doc: Add new DNSseed policy (Gregory Maxwell)
Typo, and a few "Bitcoin" -> "Bitcoin Core"

Github-Pull: #4619
Merge pull request #4582

a60120e Add built-in seeds for .onion (Wladimir J. van der Laan)