* Speedometer.cc, Speedometer.h: (GetStrProper) new method for proper unit names.
* FileCopy.cc: use Speedometer::GetStrProper for logging.
* lftp.c: document ftp:ssl-auth.
* FileCopy.cc, LocalDir.cc: use FD_CLOEXEC on descriptors.
* FtpListInfo.cc: fixed MLSD parsing for semicolons in file names.
	* FileSet.cc: allow NULL sets in certain places.
	* MirrorJob.cc, MirrorJob.h: don't create empty directories with
	  --no-empty-dirs when all source files are filtered out.