remove secondary indexes from the btree when all replica responsibilities are gone
fixing backfill of differing secondary indexes with identical names
Fix for #2899, CR 1949.
merge of #2829 remove unneeded files from test/common
merge of #2887 Test driver seems to not read all of dictionaries in Python driver
scoped_key_value_ts have to keep the buf_read_t, not just the buf_lock_t.
Merge branch 'next' into sam_2156