Merge remote-tracking branch 'couchbase/3.0.x' into 'couchbase/sherlock'

couchbase/3.0.x:
|\
| * 771859f MB-19093 [BP]: [ActiveStream] Address potential lock-inversion scenarios
| * 6811030 MB-19075: Remove printing of empty string in CouchKVStore::getMulti()

Change-Id: I06717dcaad2b764582ebe378a6f9023f7ca76d88

diff --cc src/couch-kvstore/couch-kvstore.cc
Simple merge

diff --cc src/dcp-producer.cc
Simple merge

diff --cc src/dcp-stream.cc
Simple merge