Re-implemented as a proper Wordpress feed.

This avoids serious compatibility problems with several other plugins (for example WMPL) and eliminates the need of creating a "magical" page in order to host the feed.

At this point the page will not be deleted when the plugin is updated - only when its uninstalled.
Fix a conflict with other feed plugins (e.g. Yoast SEO).
Merge pull request #9 from gabrielsomoza/master

Re-implemented as a proper Wordpress feed