Tassadar can now be used with JRuby 1.7.0.

I had some changes to do. I'll explain it here because i've made choices you can disagree with:
* Gemfile: I had to remove `ruby-debug19`, not compatible with JRuby (native extension)
* file_data.rb: Change to use `rbzip2` instead of `bzip2-ruby`
* archive_header_spec.rb: `.value` added or spec didn't pass (newer `BinData` version I guess)
* game_spec.rb: Time test commented, it did not pass, TimeZone stuffs I guess
* gemspec: standard

I hope it's as you want it would be.
Have fun

P.S: I don't know how to benchmark and compare tassadar and tassadar-pure.