Update Worker.working to handle being used in a distributed ring.

Update test suite to run either with a single server or distributed (RESQUE_DISTRIBUTED=1 rake test to run distributed)

Make sure all tests pass when running both single server and distributed.
Merge branch 'defunkt' into distributed

Conflicts:
	lib/resque/worker.rb
Merge branch 'defunkt' into distributed
Merge branch 'defunkt' into distributed
Merge branch 'defunkt' into distributed
Daemonizes when BACKGROUND environment var is set
Added documentation of daemonization
Add a notes regarding ruby >= 1.9 requirement for BACKGROUND
Show focus outline in resque server
Merge branch 'defunkt' into distributed
Merge pull request #373 from daz/patch-1

Show focus outline in resque server
Adds hoptoad_notifier and airbrake to Gemfile. Airbrake's dependencies are not defined correctly so we also have to add the i18n to the Gemfile.
Adds Airbrake support while continuing backwards compatibility for Hoptoad. Adds tests for Airbrake.
Add retry all button to failed jobs page in web UI
1.19.0
Make Resque.enqueue return something deterministic

Currently Resque.enqueue returns an empty [] or the results of the
after_enqueue_hooks that may have been run. If the before_enqueue_hook rejected
the operation we get back a nil.

This commit simply changes enqueue to return nil on rejection and true if the
job is actually queued.
Make worker use global Resque.reserve method to allow for a single point of override.
Notify jobs when they're killed due to DirtyExit

This will lead to being able to cleanup locks in the resque-lock plugin :)
Merge remote-tracking branch 'defunkt/master' into better_failure_hooks
Add before & after dequeue hooks.