Changed how ParsedInstance objects are converted to mongodb documents: if there is no deleted date attribute, it should not be present in the document at all (this will also simplify the corresponding query).
Changed how ParsedInstance objects are converted to mongodb documents: if there is no deleted date attribute, it should not be present in the document at all (this will also simplify the corresponding query).

Conflicts:
	odk_viewer/models/parsed_instance.py

kobotoolbox/kobocat,mainakibui/kobocat,awemulya/fieldsight-kobocat,qlands/onadata,piqoni/onadata,awemulya/fieldsight-kobocat,hnjamba/onaclone,eHealthAfrica/onadata,kobotoolbox/kobocat,spatialdev/onadata,jomolinare/kobocat,spatialdev/onadata,GeoODK/onadata,ehealthafrica-ci/onadata,GeoODK/onadata,eHealthAfrica/onadata,sounay/flaminggo-test,ehealthafrica-ci/onadata,piqoni/onadata,hnjamba/onaclone,spatialdev/onadata,jomolinare/kobocat,qlands/onadata,awemulya/fieldsight-kobocat,smn/onadata,GeoODK/onadata,piqoni/onadata,kobotoolbox/kobocat,sounay/flaminggo-test,qlands/onadata,sounay/flaminggo-test,smn/onadata,ehealthafrica-ci/onadata,qlands/onadata,sounay/flaminggo-test,piqoni/onadata,jomolinare/kobocat,GeoODK/onadata,ehealthafrica-ci/onadata,mainakibui/kobocat,kobotoolbox/kobocat,mainakibui/kobocat,hnjamba/onaclone,awemulya/fieldsight-kobocat,hnjamba/onaclone,smn/onadata,mainakibui/kobocat,spatialdev/onadata,jomolinare/kobocat,eHealthAfrica/onadata,smn/onadata