[kking124]

This PR includes a replacement of the RSS system provided.

RSS Feed changes:

• /rss endpoint provides maintenance and incident information
• /rss/maintenance endpoint added for just maintenance information
• /rss/maintenance endpoint added for just incident information
• add components query filter to limit the request to a specific component or list of components (e.g. ?components=2,4,7)
• add category information to rss items to describe the component (e.g. <category domain="component:2">Cachet Documentation</category>)

Settings Changes

• make the max items in the feed and the refresh rate configurable from the settings page
• add toggles to allow/deny item types from being displayed in the feed (e.g. hide completed maintenance events)

Dashboard Changes

• Add RSS links to the status page