explicitly show the text/plain utf8 mime type
move log files from var to var/log
add a getReferencedHashes function to common for finding references
fix, hashed_by values are lists
return to not considering hash collisions

This is a complication I can address later, for the time being it can be
ignored
use the getReferencedHashes function in common
add code to retrieve data from a data service as a starting point
add comment about possibly adding a binary mime type on /data/$hash