commit schemas for earlier postgresql change
remove login code from data-server

Quotas will instead be done using a much simpler secret token system
initially.
explicitly call toString('utf8') on buffers
comment out test that relies on random content to already exist
file name consistency
add blank utility function
move query function into common code
fix incorrect response of 404 in addition to 200
move sessions data into postgresql
move users data into postgresql
add users and sessions schemas