Add translation possibility / fixed bug of settings

Added some changes for correct translation possibility incl. translation for input.js.

In addition there was a small bug if the ImageCropSettings are saved with no option selected because the ImageCropSettings are empty. Now even if the options not set the saved options are set to false.

Also I changes the display of the Retina Mode settings field because as I understand did the media settings value overwrite the individual settings in the field group. Therefore the Retina Mode setting doesn't need to be displayed as the media settings always says "Yes".