* Removed `hiredis` from requirements.txt since it is not a hard requirement. Users who wish to take advantage of `hiredis` can always install it themselves, following the concept of `redis-py`.
* Added `MultiCounter`, a stateless multi-event counter, based on Redis `Hash`.
* Added `TsCounter`, a stateless timestamp counter based on Redis `Hash`, and making use of multiple keys to group timestamps, with auto expiration based on Redis key TTL mechanism.
* __Breaking Change__: `StateCounter` now has a new behavior when its objects are casted by `str` and `unicode`. `get_all()` is now `json()`. This change directly reflects the underlying change described in the next point. Also, `started` and `stopped` are now properties instead of methods.
* Simplified `techies.landmines.RedisBase` by factoring out its new child class `techies.landmines.RedisHashBase`. All Redis Hash based implementations now extends from this class to get unicode `dict` by calling `json()` method (previously `get_all()`), and unicode string serialization of the `dict` by casting the objects using `str` or `unicode` (both behave exactly the same).