ENHANCEMENTS:
+ - The daemon-mode options were separated from the normal rsync options
+ so that they can't be mixed together. This makes it impossible for a
+ user to start a daemon that had improper default option values that
+ could cause problems (a hang or an exit) when a client connects.
+
- In _exit_cleanup(): when we are exiting with a partially-received
file, we now flush any data in the write-cache before closing the
partial file.