Always exitcode 256 under Cygwin with rsync 2.6.4

[Joost van den Broek]

I've upgraded all my Windows servers with the new released cwRsync version, so 
they're all running the latest rsync now. But this version seems to ignore 
exitcodes, since my batchscript does not restart the job when a timeout 
occurs. Before, rsync did set the errorlevel on exit, so my script knew what 
to do then.

When you just give an empty rsync command, it should also exit with an exit 
code (1). But the errorlevel gets set to no. 256 instead. That couldn't be 
right.

- Joost