stress-testing loki caching

[kaczmarj]

i'm making this issue to document stress tests of the lokijs caching. please comment your observations.

here's one observation so far: what effect should the caching have? i entered a query and pressed submit. after waiting until that finished, i pressed submit again to see if it completed faster. i don't see any speed-up in the second time i pressed submit. are we aiming to cache queries?

[enemeth19]

@ericr491