Installing and configuring authoritative, recursive, and DNSSEC DNS server with Unbound

How to start unbound from Entware (I assume default prefix /opt is used). I still forward queries from dnsmasq (well it is a query forwarder) to unbound, listening to port 40. Credits in this small tip: @AndreDVJ @rgnldo @lancethepants @koitsu @jerrm

1) install unbound
2) install unbound-anchor
3) run unbound-anchor...

Installing and configuring authoritative, recursive, and DNSSEC DNS server with Unbound