* Update back end to add MQTT and WebSocket support
* Update demo project to demonstrate MQTT and WebSockets
* Update documentation to describe newly added and modified functionallity
* Introduce separate MQTT pub/sub, HTTP get/post and WebSocket rx/tx classes
* Significant reanaming - more accurate class names
* Use PROGMEM_WWW as default
* Update README documenting PROGMEM_WWW as default
* Update README with API changes
* quick and dirty WIP to investigate timezones, currently only building under esp8266 platform
much of the status stuff has been stripped for now, to test the concepts
* support set of common features across ESP32/ESP8266 WRT timezone and sntp
return dates as ISO format strings
* remove time library, and timelib fix which is no longer required
* fix the icons
* remove temporary changes to demo project
