Made i2c mode wok with the hardware I am able to test (ywrobot / sainsmart i2c LCD 2004)

Removed incorrect LiquidCrystal_I2C Library

ArduinoAddons/Arduino_0.xx/libraries/LiquidCrystal_I2C

-Subproject commit bfb71c87594ab904db9e41d9f57c6e2df89dc632

ArduinoAddons/Arduino_1.x.x/libraries/LiquidCrystal_I2C

-Subproject commit bfb71c87594ab904db9e41d9f57c6e2df89dc632

Marlin/Configuration.h

 //The LCD is attached via an I2C port expander.
 //#define LCD_I2C
 #ifdef LCD_I2C
-  // Port Expander Type - 0=PCF8574 or 1=MCP23008
+  // Port Expander Type - 0=PCF8574 sainsmart/ywrobot
   #define LCD_I2C_TYPE 0
   // I2C Address of the port expander
-  #define LCD_I2C_ADDRESS 0x20
+  #define LCD_I2C_ADDRESS 0x27
 #endif
 
 // Increase the FAN pwm frequency. Removes the PWM noise but increases heating in the FET/Arduino

Marlin/ultralcd_implementation_hitachi_HD44780.h

   #define LCD_CLASS LiquidCrystalRus
 #else
   #ifdef LCD_I2C
+    #if LCD_I2C_TYPE = 0
+      #define LCD_I2C_PIN_BL  3
+      #define LCD_I2C_PIN_EN  2
+      #define LCD_I2C_PIN_RW  1
+      #define LCD_I2C_PIN_RS  0
+      #define LCD_I2C_PIN_D4  4
+      #define LCD_I2C_PIN_D5  5
+      #define LCD_I2C_PIN_D6  6
+      #define LCD_I2C_PIN_D7  7
+    #endif
+
     #include <Wire.h>
+    #include <LCD.h>
     #include <LiquidCrystal_I2C.h>
     #define LCD_CLASS LiquidCrystal_I2C
   #else
 #define LCD_STR_ARROW_RIGHT "\x7E"  /* from the default character set */
 
 #ifdef LCD_I2C
-  LCD_CLASS lcd(LCD_I2C_ADDRESS, LCD_WIDTH, LCD_HEIGHT, LCD_I2C_TYPE);  //address, columns, rows, type
+  LCD_CLASS lcd(LCD_I2C_ADDRESS,LCD_I2C_PIN_EN,LCD_I2C_PIN_RW,LCD_I2C_PIN_RS,LCD_I2C_PIN_D4,LCD_I2C_PIN_D5,LCD_I2C_PIN_D6,LCD_I2C_PIN_D7);
 #else
   LCD_CLASS lcd(LCD_PINS_RS, LCD_PINS_ENABLE, LCD_PINS_D4, LCD_PINS_D5,LCD_PINS_D6,LCD_PINS_D7);  //RS,Enable,D4,D5,D6,D7
 #endif
         B00000,
         B00000
     }; //thanks Sonny Mounicou
+
     #ifdef LCD_I2C
-        lcd.init();
-    #else
-        lcd.begin(LCD_WIDTH, LCD_HEIGHT);
+        #ifdef LCD_I2C_PIN_BL
+            lcd.setBacklightPin(LCD_I2C_PIN_BL,POSITIVE);
+            lcd.setBacklight(HIGH);
+        #endif
     #endif
+
+    lcd.begin(LCD_WIDTH, LCD_HEIGHT);
     lcd.createChar(LCD_STR_BEDTEMP[0], bedTemp);
     lcd.createChar(LCD_STR_DEGREE[0], degree);
     lcd.createChar(LCD_STR_THERMOMETER[0], thermometer);