Change Mac OS X application bundle creation

Done to remove Java 1.6 deprecation warning within JOSM while running on 10.8.3 with both Java 1.6 and 1.7 installed.
This is done by using a fork of the Java Application Bundler (https://bitbucket.org/infinitekind/appbundler/overview).

Add Java-Runtime to application bundle so JOSM is runnable without an installed JRE