Config for rootfs and grub is not needed anymore (https://dev.openwrt.org/ticket/18074)
Config file not needed anymore (set implicitly by gluon now)
Avoid empty vars
This still needs some work:
- there's no factory image causing `make images` to fail
- VoCore can not support BSS and IBSS at the same time
- multi-BSS mode (e.g. mesh + BSS) works if the macs only
differ in the last 3 bits. Gluon expects to choose both MACs freely,
though, so after flashing the image one should reset the wifi MACs.
This is further complicated as VoCores have their MACs assigned
without gaps making collisions likely.
- there are no buttons nor ethernet ports (without the dock, that is),
so config-mode will not be possible as is
