ActiveSupport.escape_html_entities_in_json from true to false to match previously announced Rails 3 defaults [DHH]

[#2982 state:committed]
Signed-off-by: NJeremy Kemper <jeremy@bitsweat.net>

hash/conversions.rb needs active_support/core_ext/string/inflections because it uses singularize and a few others

requires active_support/inflector/methods active_support/core_ext/string/inflections in local_cache.rb because it uses underscore

requires active_support/core_ext/array/extract_options in mem_cache_store.rb because it uses extract_options!