Demonstrate that the Extractor can harvest stats from another web application

One of the fundamental requirements of the JMX Data Mart project is that when the Extractor is deployed as a web application, it should be able to extract MBeans values from other web applications.  These changes demonstrate that point.  First off, I had to do a little bit of refactoring of the Extractor class so that it could be launched in the jmx-extractor-webapp web application.  I also made additional use of Google Guice for dependency injection and added logback/SLF4J for application logging.

Overall, these changes continue to build the project infrastructure so that when development begins in earnest, we'll have a good foundation to build upon.