Issue #1040534 by catch, Owen Barton, danreb, mikeytown2, ogi, omega8cc, xjm: Rewrite rules for gzipped CSS and JavaScript aggregates cause lots of lstats for files that will never exist

Issue #2639878 by RobLoach, omega8cc, memtkmcc: Use less demanding check to see if OPcache is active

Issue #1559116 by omega8cc, mva.name, droplet, Xano, mgifford: Make core aware of Nginx and PHP-FPM to avoid confusing alerts