Pull request for Issue 114

Hello,
After talking to Dr. Mesbah, we are resubmitting the pull request.  I've done my best to address the issues you brought up:

-I removed using System from the code, and we're now using the logger

-We copy/pasted (and modified) code licensed under the Apache license, which means that you are free to sell/modify/do basically whatever you want with that code so long as that message is left in the code. I hope that isn't an issue.

-I made sure that we used the formatter for files that we touched.

- We are still using our loader classes because after talking to Dr. Mesbah, it is closer to the intended functionality, and does not require the use of a meta file in a plugin.  
- I have changed it to search through the classpath, which wasn't what Dr. Mesbah and I had discussed, but I do not have time before todays deadline to change it back to searching through a specific folder like it was doing previously.

- I wasn't sure which test needed to be updated.  The tests that have been included currently pass

- If a plugin belongs to multiple types (it inherits from multiple plugin interfaces), it will be added to each type of interface (I've changed our simple demo plugin class to inherit from both interfaces that are run precrawl so that this can be verified easily).

- I wasn't sure what you meant by making an option in the CrawljaxConfigurationBuilder.