The RandomQueryConfig has its own seeded RNG, but we didn't always use
it (especially in the last two commits, but also I think in one previous
thing), so let's use it more consistently.
We check for int fields (as opposed to decimal), and if we find them,
we add Distinct to our list of potential queries to use if and only
if we've got a depth of at least one so there'd be a child query under
the current query, and if we do, grab one of the int (not decimal)
fields and do a query on that.
For time fields, allow specifying a range of times, then 19/20 times,
specify "from" and "to" times in that range when querying those fields,
rather than just looking at the standard view all the time.
More generally, report QPS not at 0 queries, which is boring, but every
100 queries *and* after the last query if the last query wasn't at a
multiple of 100 queries. Makes the output slightly more useful, I think.
