Better support for multipart key/value combinations (representing AND conditions for filtering) in permission objects.
Added management command to increment namespace version keys (for mass cache invalidation)
Fix for permissions loop overwriting the base class and causing any iterations after the first to fail
Fix for a permissions issue
Group model now has a field to hold base context variables, to be used when formatting values in permissions
additional model properties to return base class names (singular and plural) for polymorphic subclasses
Refactored cache system. lots of backwards-incompatible changes. cache key generation is now available via classmethods (for generating keys using raw data) and as instance properties on objects
cache key testcase methods now use cache.make_key for checking presence of keys
Merge commit '6fd51c82f7bc856e7dc24c1aa76a250fa5335980' into develop