#273618 by Nick_vh: Fixed checking for gzip in both the content and in the browser request.
#288318 by Jo Wouters: Fix for wildcard replacement.
#313289 by Murz: Fix for wrong check for $map initialization. We should be checking $this->map not $map.
#277078 by Murz: Cache items prefix with APC cache type
#325614 by R. Muilwijk : Fix for updating static cache on set. and Fix for locking problem with all engines.