Merge pull request #583 from keltia/rbx-2.2.9

Add rbx-2.2.9, 2.2.8 was skipped due to broken wrappers.

share/ruby-build/rbx-2.2.9

+install_package "yaml-0.1.6" "http://pyyaml.org/download/libyaml/yaml-0.1.6.tar.gz#7da6971b4bd08a986dd2a61353bc422362bd0edcc67d7ebaac68c95f74182749" --if needs_yaml
+install_package "rubinius-2.2.9" "http://releases.rubini.us/rubinius-2.2.9.tar.bz2#7b01a7f2508167e73b5273b4e55e6616fc7fd975e79c84c4d2e3ef83d849d2ce" rbx