Make ESP8266 use LittleFS instead of deprecated SPIFFS
Make framework use the correct filesystem automatically and handle the call the FS.begin()
Change default MQTT keepalive to 60 seconds
Fix lodash security issue
* Add framework for built-time feature selection
* Allow MQTT, NTP, OTA features to be disabled at build time
* Allow Project screens to be disabled at build time
* Allow security features to be disabled at build time
* Switch to std::function for StatefulService function aliases for greater flexibility
* Bump various UI lib versions
* Update docs
