JRuby dependencies

This project just contains a simple file for use in packaging up an uberjar which has just JRuby-specific dependencies that Puppet Server needs. The uberjar specifically excludes some dependencies that Puppet Server already uses, like joda-time and org.yaml/snakeyaml, in order to allow Puppet Server to provide its own preferred versions. This project allows Puppet Server's "release" uberjar (which excludes JRuby-specific dependencies) to be run in combination with the JRuby dependencies uberjar on the same Java classpath. This allows the specific version of the JRuby dependencies uberjar to be swapped out at run-time, e.g., for switching between the use of a JRuby 1.7 vs. a JRuby 9k dependencies jar. Dependencies for JRuby 1.7 are managed in the 1.7.x branch whereas dependencies for JRuby 9k are managed in the 9.x branch.