Merge pull request #424 from techtonik/patch-1

README.md: Fix Rescue URL
Pass the default worker connection into the started and finished registries

In practice all the registry methods are called with pipelines, but if no
connection is passed in when instantiating the registry and the connection
stack is empty resolve_connection will raise NoRedisConnectionException.
make job description unicode friendly
fix decode
fix decode error in py3.
Merge pull request #438 from adamwen829/master

fix issue #437
Merge pull request #431 from negz/worker-redis-bug

Pass the default worker connection into the started and finished registries
allow depends_on to be a job id or a job itself

Other parts of the code (i.e.: the `.create()` method) allow the `depends_on` kwarg to be a `Job` object *or* a job id. This is an attempt to allow that same idea within the `.enqueue_call()` method for a queue. Since this part of the code requires actually knowing the precise redis key for the job that's depended on, my intuition is that a `.fetch()` is the only way to solve this.
use internal job_class for check
add PyCharm .idea folder to .gitignore
test for id based job dependancies
Merge pull request #445 from conslo/patch-1

allow depends_on to be a job id or a job itself
instantiate a job instead of fetch

this removes the need for the depended on job.id already being saved
no need for that save anymore
Ensure the FinishedJobRegistry honors an 'infinite' result_ttl of -1
Merge pull request #455 from negz/spotify-freeze

Ensure the FinishedJobRegistry honors an 'infinite' result_ttl of -1
Merge pull request #451 from conslo/depend-on-unsaved-job-ids

Depend on unsaved job ids
Any negative number should cause a job to live forever in a registry.

While the documentation explicitly mentions ttl=-1, this matches better the behaviour of the job.cleanup() method.
Rename registry timeout to registry ttl

This matches job.cleanup() better and (I think) makes the purpose slightly clearer.
Allow maximum job age to be specified when cleaning up or getting expired jobs from a registry.

This ensures that all jobs cleaned from a started registry end up in the failed queue.