Abstracted ground to Ground.java that takes care of physics properties. Refactored some util methods out of Model.
Uploading ini4j dependency for parsing ini files.
Added default ini file and modified all calls to settings to use our new settings mechanism.
Minor refactor. Moving ground to a different package, adding comments.
Removing debug output. Synchronizing calls to getInstance() in Settings.
Merge pull request #30 from jtmzheng/settings+refactor

Custom settings file + some refactor