ruby-build 20140524

Merge pull request rbenv#573 from hone/ruby-1.9.3-p547

added definition of 1.9.3-p547

Merge pull request rbenv#567 from sstephenson/2-0-0-p481

Added definition of 2.0.0-p481

ruby-build 20140509

ruby-build 20140420

ruby-build 20140408

ruby-build 20140405

ruby-build 20140225

ruby-build 20140224.1

ruby-build 20140224