Add settings and implement grblHal to act as DHCP server

[siganberg]

This is very useful for a direct Ethernet connection to a device such as a Pi, which by default uses DHCP client network settings.

grblHAL will assign an IP address automatically, so the user does not need to mess around with assigning a static IP address to the Pi.

This can also be turned off if the user prefers the other way around, where grblHAL acts as a DHCP client which already what we have right now.

[karoria]

I think this is already in place. Use $304 setting to configure. Use $304=1 to force DHCP or $304=0 for a static IP address (requires setting $301, $302, $303 for IP, Gateway, Netmask).

[siganberg]

Thats is DHCP client mode, not DHCP server mode.

[terjeio]

I'll put this on my todo list for Ethernet connections (I do not have one at the moment), WiFi AP mode already supports DHCP server.

[karoria]

Thats is DHCP client mode, not DHCP server mode.

Ok. I was not aware of that. I use static ip always. Thought DHCP is for dhcp server mode.

[terjeio]

DHCP server for static IP mode ethernet was added two weeks ago.