RSS Bundler hooks

This post serves two purposes:

To announce a new RSS Bundler feature
To test said RSS Bundler feature

RSS Bundler now allows the user to configure a program as a "hook". This program will run every time a new post is detected by RSS Bundler (this detection is GUID-based, as such it will only work for feeds that include GUIDS on their posts). Various environment variables will be set according to the properties of the post (ex. author, title, description, etc.). More hooks will potentially be added in the future.