* 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
Adds a webpack plugin to package interface as PROGMEM into a header file in the framework.
Adds a build flag to optionally enable serving from PROGMEM or SPIFFS as required
Adds documentation changes to describe changes
use size_t for size as async web server uses this type internally
use uint8_t for provision mode, we only have 3 values
address warnings about ordering initializers