Converted the project to use Maven and performed some housekeeping.

* The project now uses Maven for dependency and build management so the Ant Buildfile has been removed.
* Apache Commons Codec is now used for Base64 encoding and the ```com.bigcommerce.utils``` package has been removed.
* The ```HttpURLConnection``` is not disconnected immediately so the associated ```InputStream``` can be read.
* Two example tests were added, and the debugging tests were removed.
* A project-wide cleanup was performed, removing unused imports and commented code.