improve couchdb_datastore by removing extra reads prior to writing, caching db, and simplify logging
improve couchdb_datastore by removing extra reads prior to writing, caching db, and simplify logging

scionrep/scioncc,ooici/pyon,scionrep/scioncc,mkl-/scioncc,crchemist/scioncc,mkl-/scioncc,crchemist/scioncc,ooici/pyon,scionrep/scioncc,mkl-/scioncc,crchemist/scioncc