Don't use winston's handleExceptions option

When this option is enabled, stack traces end up being compressed onto a
single line, which makes it very difficult to figure out what the actual
error was. This doesn't affect the actual process, which will still exit
after an uncaught exception, as it did with this option enabled.
Add logging to the popit-daemon-debian init script

This will hopefully give a bit more of an insight into why the process
sometimes restarts. The solution was adapted from this SO answer [1].

[1] http://stackoverflow.com/a/12662904
Always send logs to stdout/stderr

Rather than trying to log to a file from within node, just send the logs
to the console and let the init script handle where they are sent after
that.
Don't log errors twice

Express already logs the error to the console, so there is no need to do
this twice.
Check membership's organization exists before using

This was causing the process to crash when a membership referenced an
invalid organization. To prevent that we now check for an organization
before trying to get its name.
Merge branch 'fix-503-errors'