* Correct checking of the AP password and SSID lengths.
* Only enable AP mode if it is really configured enabled.
* Only start the http server if wifi is enabled.
This patch gets the newlib standard stream descriptors playing well with the
lwip socket descriptors and the spiffs file descriptors. The LWIP_SOCKET_OFFSET
is now defined to be 3, rather than zero, to avoid clashing with the standard
stream descriptors, and the SPIFFS_FILEHDL_OFFSET is bumped up to start after
the lwip descriptors.
