This project is archived now
I am no longer maintaining it.
Basically all WereCatf and Rob Tillaart work, stripped of things not related to ESP8266 and adapted to Sming framework.
For documentation see original sources, nothing has changed in library interface.
Sming already includes I2CIO.h used in LiquidCrystal library. This one has more features and adds support for PCF8575.