Merge pull request #1 from emabrey/master

Maven Build Environment Changes
Updated .gitignore
Removed @Override annotation (Java-6+ only) + added mp3plugin.jar that is needed for playing mp3 sounds
Removed JMF and implemented JLayer sound library.

JMF has been replaced by the JLayer sound library, and the code used to play audio has been updated to reflect this. The mp3plugin codec dependency, no longer needed since we are not using JMF, has been removed from the project.