Also adds source code for sdk_cnx_rc_search, adding a null pointer dereference
check (that is not expected to be seen), and source code for sdk_cnx_remove_rc.
Function sdk_eagle_auth_done accesses the netif-flags and the NETIF_FLAG_DHCP flag removed in lwip v2, and also the netif->ip_addr so is needed for lwip development.
Function sdk_wpa_config_bss accesses the netif->hwaddr.
Also code for a few other trivial functions that help debug the dhcpc paths.
