Implement SDK event monitor
Move wifi status event monitor code into seperate file
(app/modules/wifi_eventmon.c)
Modify wifi lua callback registration code.
Add Functions wifi.ap.deauth and wifi.sta.getrssi
Rework wifi event monitor to use tasking interface
fix for Lua coroutine compatibility issue
Made changes Suggested by TerryE
Also, moved code that sets the default host name out of
luaopen_wifi_init and into a separate function and added a post_task_low
entry in it's place.
Replaced some if test then return error lines with
luaL_argcheck
Add check for malloc null return in wifi.eventmon
to catch out of memory errors
Added Lua module rtctime to interface with it.
This keeps as accurate time as is possible on the ESP8266, including across
deep sleeps (provided rtctime.dsleep() is used rather than node.dsleep()).
Intended to be used together with NTP for high accuracy time keeping. The
API is via rtctime.{get,set}timeofday(), working from Unix epoch.
Note that 160MHz CPU clock is not currently supported by the rtctime code,
as it is only aware of the 52MHz boot clock and the regular 80Mhz default
clock.
See rtctime.h for detailed info on how this all works.