Fixed: table cells were not initialized from xib settings

This is a second attempt to fix the problems addressed by 69bbe627a9e10fc78af3cda2b8c7b4a821eed8ed.

Because table cell classes needed to use the same initialization code as the NS_initWithCoder methods, it was necessary to refactor the initialization code into separate NS_initWithCell methods and call them separately from NS_initWithCoder.