[arch-dev-public] moving dhcpcd to [extra]?

[Antonio Rojas via arch-dev-public]

Is there any reason to keep dhcpcd in [core]? It's only an optional 
dependency of netctl in [core], it currently lacks an active maintainer, it 
doesn't seem to be much used (given the slow pace of signoffs), and there's 
already a basic dhcp tool in [core] (networkd). 

Any objections to move it to [extra]?