savedir: new symbol for fast-read version * lib/savedir.h (SAVEDIR_SORT_FASTREAD): New symbol, for programs like GNU cp that want to use SAVEDIR_SORT_INODE if available, SAVEDIR_SORT_NONE otherwise. Problem reported by Bernhard Voelker in: http://lists.gnu.org/archive/html/coreutils/2014-02/msg00037.html