update Gemfile
add almost working java implementation
first working prototype of Java implementation

- specs are green
- fixed all parsing issues
- replaced cities lookup with a HashMap
- missing:
-- Cache handling
-- isp-string memory usage optimization
csv parsing + data structures complete
TODO: caching + benchmarks
finish geoipdb java extension
Version bump to 0.5.0
Merge branch 'jruby'

Conflicts:
	.gitignore
	.rvmrc
	Gemfile
	Rakefile
	geoipdb.gemspec
version bump