Ruby 1.8.7 compatibility tweaks
Update TODOs
Remove unnecessary requires
Gem overhaul - prepping for future development

* Use instances rather than class-methods throughout
* Rename "loaders" module to "sources"
* Fix test failures due to refactoring
* Incorporate `WebMock' to better test URI based "sources"
* Formatting
* Build on ruby-1.9.2 on Travis-CI
* Set version to 0.3.0.alpha