added boilerplate and refactored QueryDelta test to use it
changed convertObjectID to objectIDToString, added stringToObjectID
refactored QueryPayload and QueryDelta to use boilerplate
created QueryStream
added rMissing, lMissing
removed mori dependency - lodash does set computations
don't use ObjectID except in query construction
factor out formatPayload
fixed bug in lMissing/rMissing
corrected order on test
(hopefully) doing a better job of hiding delete events
QueryStream.update supports idSet add/remove
normal format splits out oplist, added format test