* 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
* interactive example: update with option for using DHCP again after using static IP
* lwip2: avoid crash when IP address is set to 0(any) by dhcp not getting its lease renewal in due time
* lwip2: automatically remove oldest PCBs in time-wait state, limit their number
thanks to @me-no-dev 07f4d4c241 (diff-f8258e71e25fb9985ca3799e3d8b88ecR399)
* faq: update about tcpCleanup()
* lwip2: add a macro HAS_PHY_CAPTURE=1 indicating capture facility is available
