v 4.6.0
v4.6.0 * Validate time zone in quickDT prior to guessing offset (#1575) * Use getPrototypeOf instead of __proto__ (#1592) * Perf: Memoize digitsRegex (#1581) * Add DateTime.buildFormatParser and DateTime.fromFormatParser (#1582) * Perf: Use computed offset passed in DateTime constructor (#1576) * Update interval.js doc per #742 (#1565) * Added some JS doc for time zones (#1499) * Fix cutoff year docs * Perf: Cache ts offset guesses for quickDT (#1579)