Add benchmarking script #2358
Cache for getValuePercent missed hit it shouldn't #2358

If asking for a questionnaire data, but another questionnaire had no
answer at all, then the cache was not filled for the second questionnaire.
This lead to an extra SQL query when asking data for the second
questionnaire, whereas we should already have it in cache.

We now ensure that we get all questionnaire for a Geoname in cache, even
empty questionnaire. This avoid a few queries but does not improve speed
significantly.
Mass fetch questionnaire's geoname #2358

We fetch all questionnaire for one geoname at once. This a few queries,
but does not significantly improved speed in most common cases.
Add cache on formula computing on regression level #2358

This may gives a huge boost in speed depending on the rules used.
This is the case for Water which is almost 10x times faster
for /api/table/country.