* fhandler.h: Rename FH_W95LSBUG flag to FH_LSEEKED.

	* fhandler.h: Rename FH_W95LSBUG flag to FH_LSEEKED.
	(fhandler_base::set_did_lseek): Rename from set_check_win95_lseek_bug.
	(fhandler_base::get_did_lseek): Rename from get_check_win95_lseek_bug.
	(fhandler_base::set_fs_flags): New method.
	(fhandler_base::get_fs_flags): Ditto.
	* fhandler.cc (fhandler_base::write): Make 64 bit clean.  Convert file
	to a "sparse" file when writing after a long lseek (>64K) beyond EOF.
	(fhandler_base::lseek): Call set_did_lseek() instead of
	set_check_win95_lseek_bug().
	(fhandler_base::fhandler_base): Initialize fs_flags to 0.
	* fhandler_disk_file.cc (fhandler_disk_file::open): Don't create files
	as "sparse" unconditionally.  Set fs_flags member.