move modeString to the File class, since it needs the lsTag provided by its decendents add assertion to ensure that the File class can't be instantiated
move modeString to the File class, since it needs the lsTag provided
by its decendents
add assertion to ensure that the File class can't be instantiated

sassoftware/conary,sassoftware/conary,sassoftware/conary,sassoftware/conary,sassoftware/conary