Added implementation for `fileSeparator` (#251)
Added implementation for `fileSeparator` (#251)

ceylon/ceylon.language,ceylon/ceylon.language,lucaswerkmeister/ceylon.language,jvasileff/ceylon.language,lucaswerkmeister/ceylon.language,jvasileff/ceylon.language,unratito/ceylon.language,unratito/ceylon.language