ets scalability benchmark, measuring insert, lookup and delete
operations separately
fix counting number of keys and operations done per worker
somewhat updated configuration
for fixed benchmark lookup times are much higher

Conflicts:
	bench/ets_bench/src/ets_bench.erl
ets_bench: add more flexible setting of number of workers
ets_bench: mixed operations mode possible

Conflicts:
	bench/ets_bench/src/ets_bench.erl
ets_bench bugfix: mixed reverted to insert
cleanup so benchmark works properly with R16B
also changed configuration to run slightly faster
and run benchmark with multiple settings for lookup/update ratio