* lwip2: better handling of ipv4_addr/t type + 3 sntp servers
* bump lwip2 version
* Only with FEATURES=1: 3 sntp servers and AutoIP enabled (169.254 when dhcp server fails)
* Only with FEATURES=1: 3 sntp servers and AutoIP enabled (169.254 when dhcp server fails)
* local CI runner: select build type
* new ipv4_addr/t definition makes things easier for IPAddress
* update local CI runner
* lwip2 changes
* lwip2: port esp-ping and espconn
* restore definition of ip_addr (=ipv4_addr) when IPv6 is not enabled
* overload IPAddress:operator == and != to avoid ambiguousness
* brings lwIP's INADDR_NONE (which is IPv4 255.255.255.255, suposed to be invalid address but it is)
* inet_aton is a lwIP define, rename Ethernet DNS implementation of this to prevent name collision
that's because IPAddress now includes lwip/inet.h
This includes empty stubs for most core Arduino functions.
Need to actually implement all those digital reads writes whatever.
Need to prebuild toolchains (xtensa-elf-lx106) for 3 platforms and put them on some download server.
Need to do the same with esptool.
Need to fix 0x40000 binary generation and add correct upload commands.
Maybe even implement uploads over WiFi.
