Flask-cache

- Port to Python >= 3.3 (requiring Python 2.6/2.7 for 2.x).
- Fixed bug with using per-memoize timeouts greater than the default timeout
- Added better support for per-instance memoization.
- Various bug fixes

- Changes jinja2 cache templates to use stable predictable keys. Previously
the key for a cache tag included the line number of the template, which made
it difficult to predict what the key would be outside of the application.
- Adds config variable `CACHE_NO_NULL_WARNING` to silence warning messages
when using 'null' cache as part of testing.
- Adds passthrough to clear entire cache backend.

- Bugfix for using memoize on instance methods.
The previous key was id(self), the new key is repr(self)

- Fail gracefully in production if cache backend raises an exception.
- Support for redis DB number
- Jinja2 templatetag cache now concats all args together into a single key
instead of treating each arg as a separate key name.
- Added delete memcache version hash function
- Support for multiple cache objects on a single app again.
- Added SpreadSASLMemcached, if a value is greater than the memcached threshold
which defaults to 1MB, this splits the value across multiple keys.
- Added support to use URL to connect to redis.

- Added warning message when using cache type of 'null'
- Changed imports to relative instead of absolute for AppEngine compatibility

- Added `saslmemcached` backend to support Memcached behind SASL authentication.
- Fixes a bug with memoize when the number of args != number of kwargs