Nothing outside the config mode depends on luci-base anymore.

We also make use of the boolean support of simple-uci to make scripts
clearer.

Fixes #886

Fixes #854

Using service_start requires exporting of environment variables.

Fixes #397

This avoids poking dnsmasq every time a DHCP lease is obtained or a router
advertisement received.

This package provides a secondary dnsmasq instance on port 54 which resolves
everything over the WAN interface.