Merge branch 'develop' into mongodb-3.6

SConstruct

bench/workgen/runner/runner/__init__.py

bench/workgen/runner/runner/core.py

bench/workgen/runner/workgen_stat.sh

bench/workgen/workgen.cxx

bench/workgen/workgen.h

bench/workgen/workgen_func.c

bench/workgen/workgen_func.h

bench/workgen/workgen_int.h

bench/workgen/wtperf.py

bench/wtperf/idle_table_cycle.c

bench/wtperf/wtperf.c

bench/wtperf/wtperf.h

dist/api_data.py

dist/flags.py

dist/s_stat

dist/s_string.ok

dist/stat_data.py

examples/c/ex_thread.c

src/btree/bt_read.c