Code review comment for lp:~statik/ubuntu/karmic/couchdb/fix-bug427036

This adds a new variable in /etc/default/couchdb to control whether couchdb is started at boot or not - most desktop installs will not need couchdb started at boot so this is a nice compromise. It seemed simpler that splitting the init script into a separate binary package, and a few other packages such as pulseaudio, monit, and fetchmail seem to do the same thing.