Added dependency and basic configuration for Resque-scheduler gem.

Resque-scheduler is configured to allow dynamic changes to the scheduling. This allows us to add scheduled jobs for refreshing every time a feed is created, and to destroy such jobs every time a feed is destroyed. These dynamic changes to the scheduling are not yet implemented.
When a new feed is created in the database, a job to update it in background is scheduled to run hourly. When a feed is destroyed from the database, the job that updates it is unscheduled.

The first run of the job will be a random amount of minutes (between zero and 60) after creating the database, and after that every hour. This means that feed update jobs will be randomly spread over every 1-hour period, to spread server load as evenly as possible. Maybe in the future we can implement a smarter algorithm to determine the optimal time to schedule hourly updates.

Also, the code that stubs some methods (to avoid any HTTP calls or Redis calls during testing) has been moved from individual spec files to the shared spec_helper.rb file. This way such methods are stubbed in all tests, without having to remember to stub them in every spec file.
God gem is used to start and monitor the following background processes: Redis-server, resque worker for the :update_feeds queue, and resque scheduler.

When deploying with Capistrano, God is restarted in the remote server.

The God notification configuration is a per-environment file (it will be overwritten during deployment in staging and production with the version of the file that has been copied by hand to the server). This is because we intend to send email notifications through Amazon SES and I don't want SES SMTP credentials to be present in Github.
Changed the moment in which the redis working dir is created during deployment.
Fixed an error in the capistrano deployment script.
Changed gemset name in .rvmrc from "openreader" to "feedbunch".
Changed capistrano deployment script to set the correct RVM gemset just before invoking the 'god' binary. It should fix a bug I'm getting on deploying.
Require rvm/capistrano before bundler/capistrano. Hopefully this will make the deployment script RVM-aware before running "bundle install", and hopefully this will result in gems being installed in the correct RVM gemset.

This should help with the problems the deployment is having trying to find the "god" binary in the remote server.
More changes to capistrano deployment to try to get God to work.
More tweaking to get God and Capistrano to play nice with each other.
More tweaking to get God and Capistrano to play nice with each other.
More tweaking to get God and Capistrano to play nice with each other.
More tweaking to get God and Capistrano to play nice with each other.
More tweaking to get God and Capistrano to play nice with each other.
Pass the rails environment to the resque workers when starting them with God.

Redis configuration is not in the shared/redis deployment folder, but rather in the current/redis folder. This way it will be overwritten every time a deployment happens. However the aof and dump redis files are in the shared/redis folder, so that no redis data is lost when deploying.

Changed redis config file to better match the redis-server version installed in the production and staging servers.
Fixed an error in God configuration: the group to be notified when a watch is flapping is "admins", not "admin".
Fixed broken acceptance test.

A line that stubbed FeedClient.fetch had been deleted by mistake when moving stubbing code to spec_helper.rb in commit b9bdca573eb0945133d213d4e722e5c3760fc32a
Updated nokogiri gem from 1.5.9 to 1.5.10
Include tlsmail gem, to enable TLS email sending in God notifications.

TLS support, which God doesn't include by default, is a must to be able to send emails through Amazon SES.

The notifications.god file in production and staging environments will have the necessary God configuration. This configuration will not be present in Github, because it is confidential.
Protected access to the Resque web console using the Cancan gem.

This has required adding an "admin" boolean attribute to the User model (and table). Only users that have the "admin" attribute with a true value will see the Resque link in the navbar, and any attempt to access its URL by non-admin users will be stopped.

The solution adopted is inspired in this blog post:

   http://simple10.com/resque-admin-in-rails-3-routes-with-cancan/