Additional haystack options/fixes

@simod and anyone else, feedback/suggestions welcomed on this (as always!)

Added optional setting to update facet counts based on results when using Haystack (HAYSTACK_FACET_COUNTS)
Renamed optional setting to turn off security permission pre-filtering (SKIP_PERMS_FILTER), and check for this setting when getting facet counts
Simplified/fixed Haystack bbox filtering
Fixed haystack indexing of keyword values