Handle paths with spaces

Some quoting in server_loop that should fix this.  (And preventive
quoting in the command scripts in case the basedir changes.)

So far I've spot-tested these changes with some sample files/directories
and also checked against a regression in my current server setup.
Haven't yet tested a real server setup that uses paths-with-spaces.
Warn that myip can only handle one interface

Yup.
More comments about using init scripts (or not)

Mention that servers launched through init scripts are daemon processes,
while servers started manually through a command script are foreground.
Pros and cons.