racket/class: doc fixes and improvements
racket/class: doc fixes and improvements

 - actually fixed the grammar this time
 - examples for most class/object utils
 - consistency with naming conventions
 - interface ctc example

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket