Split out config and data dirs
Linux standard practice says to put config in /etc/ and variable data in /var/. Similarly, the XDG basedir spec says config should go in $XDG_CONFIG_HOME, while data should go in $XDG_DATA_HOME.
For portability, we could provide some sort of a config option (e.g. an envronment variable such as ONIONR_PORTABLE_HOMe) that causes the directories to be overridden to be within the specified directory.