Huey

* Fix task `repr` (refs 460).
* Adds task-id into metadata for task exceptions (refs 461).
* Ensure database connection is not closed when using the `call_local` method
of Django helper extension `db_periodic_task()`.
* Allow pickle protocol to be explicitly configured in serializer parameters.
* Adds `FileHuey` and full `FileStorage` implementation.
* Add `shutdown()` hook, which will be run in the context of the worker
threads/processes during shutdown. This hook can be used to clean-up shared
or global resources, for example.
* Allow pipelines to be chained together. Additionally, support chaining task
instances.

[View commits](https://github.com/coleifer/huey/compare/2.1.3...2.2.0)

* Fix semantics of `SIGNAL_COMPLETE` so that it is not sent until the result is
ready.
* Use classes for the specific Huey implementations (e.g. `RedisHuey`) so that
it is easier to subclass / extend. Previously we just used a partial
application of the constructor, which could be confusing.
* Fix shutdown logic in consumer when using multiprocess worker model.
Previously the consumer would perform a "graceful" shutdown, even when an
immediate shutdown was requested (SIGTERM). Also cleans up the
signal-handling code and ensures that interrupted tasks log a warning
properly to indicate they were interrupted.

[View commits](https://github.com/coleifer/huey/compare/2.1.2...2.1.3)

* Allow `AsyncResult` object used in `MiniHuey` to support the `__call__()`
method to block and resolve the task result.
* When running the django `run_huey` management command, the huey loggers will
not be configured if another logging handler is already registered to the
huey namespace.
* Added experimental contrib storage engine using `kyoto tycoon <http://fallabs.com/kyototycoon>`_
which supports task priority and the option to do automatic result
expiration. Requires the `ukt <https://github.com/coleifer/ukt>`_ python
package and a custom kyototycoon lua script.
* Allow the Sqlite storage engine busy timeout to be configured when
instantiating `SqliteHuey`.

[View commits](https://github.com/coleifer/huey/compare/2.1.1...2.1.2)

* Ensure that `task()`-decorated functions retain their docstrings.
* Fix logger setup so that the consumer log configuration is only applied to
the `huey` namespace, rather than the root logger.
* Expose `result`, `signal` and `disconnect_signal` in the Django huey
extension.
* Add `SignedSerializer`, which signs and validates task messages.
* Refactor the `SqliteStorage` so that it can be more easily extended to
support other databases.

[View commits](https://github.com/coleifer/huey/compare/2.1.0...2.1.1)

* Added new contrib module `sql_huey`, which uses `peewee <https://github.com/coleifer/peewee>`_
to provide storage layer using any of the supported databases (sqlite, mysql
or postgresql).
* Added `RedisExpireHuey`, which modifies the usual Redis result storage logic
to use an expire time for task result values. A consequence of this is that
this storage implementation must keep all result keys at the top-level Redis
keyspace. There are some small changes to the storage APIs as well, but will
only possibly affect maintainers of alternative storage layers.
* Also added a `PriorityRedisExpireHuey` which combines the priority-queue
support from `PriorityRedisHuey` with the result-store expiration mechanism
of `RedisExpireHuey`.
* Fix gzip compatibility issue when using Python 2.x.
* Add option to `Huey` to use `zlib` as the compression method instead of gzip.
* Added `FileStorageMethods` storage mixin, which uses the filesystem for task
result-store APIs (put, peek, pop).
* The storage-specific `Huey` implementations (e.g. `RedisHuey`) are no longer
subclasses, but instead are partial applications of the `Huey` constructor.

[View commits](https://github.com/coleifer/huey/compare/2.0.1...2.1.0)

* Small fixes, fixed typo in Exception class being caught by scheduler.

[View commits](https://github.com/coleifer/huey/compare/2.0.0...2.0.1)