Emit error row for a null doc id in POSTs to _all_docs
Emit error row for a null doc id in POSTs to _all_docs

This is compatible behavior with CouchDB 1.x

Jira: COUCHDB-3039
BugzID: 68486

fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb