Feature: RssService should have multiple timers

[FuzzicalLogic]

RSS Feeds are often auto-managed by a variety of entities, each with its own security policy based on request limits. Setting a specific time interval for all Feeds runs two potential risks:

• The interval for one may violate the policy of another
• In order to avoid the policy of one, you may increase the interval time but this can cause issues with timely updates for the more liberal services.

We recently ran into this problem with pathofexile.com, where our timer was too frequent, causing the IP of POE-Bot to be banned. Adding a timer to each Feed independently would allow the bot to keep timely on faster services, but conform to the restrictions of the others.