Added Support for sanguinololu + panelolu2

- Added Support for sanguinololu + panelolu2 [ FEATURE_CONTROLER 15]
- Added #define UI_I2C_HOTEND_LED UI_I2C_HEATBED_LED UI_I2C_FAN_LED to
enable LED status update via I2C [used by FEATURE_CONTROLER 15 and 5]