I am Fotis from the codebender team. The LiquidCrystal_I2C library hosted by codebender is this one http://hmario.home.xs4all.nl/arduino/LiquidCrystal_I2C/
. The library you are trying to use seems to be this one http://www.argeduino.com.ar/download/LiquidCrystal/
, which includes LiquidCrystal_I2C.
By default, the first one is used when you "#include <LiquidCrystal_I2C.h>".
However, you can add the second library to your account as a personal one, which should make your project compile successfully.
See this article for more info http://codebender.uservoice.com/knowledgebase/articles/399209-personal-libraries