Functional refactoring

* Misc bug fixes
* Refactored to use generators
* Fixed pep8 errors
* Added speedparser as optional replacement for feedparser 
* Added lxml parsing
* Added `context.describe_dependencies`
* Updated, fixed, and rearranged tests
* Removed broken tests
* Downloaded source data and refactored tests to work offline
* Added some Py3 compatibility
* Removed internal pipe dependencies
* Rearranged some folders 
* Added a `DotDict` class to abstract away dot notation style dictionaries
* Updated README