Ant build

* Download the proper ANTLR 3 dependency from antlr.org if it's not already present in `lib/`
* Remove `build.properties` from source control
* Allow user to create a `user.build.properties` for custom properties to the Ant build (this is in `.gitignore`)
* Added up-to-date checks for ANTLR 3 code generation, compilation, and jar packaging
  * Removes the need to pass `-make` to the v3 tool