Arduino Libraries for I2C LCD

Libraries so Arduino can compile the sketch to work with the PCF8574T
IIC  20*4 LCD Display
Support for IIC 20*4 LCD (PCF8574T  Chip)

Relevant changes to add support for PCF8574T IIC 20*4 LCD. Includes
adding a new feature controller (No.16) and new display type (No.6).