improve merging of snips when a style change is applied to a range (as by the syntax colorer)
improve merging of snips when a style change is applied to a range (as by the syntax colorer)

svn: r4871

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