This is latest stable release of Ruby and it basically compatible with
Ruby 1.9.3. Please refer full changes to NEWS/ChangeLog files or official
Web site. Here is language changes:
* Added keyword arguments.
* Added %i and %I for symbol list creation (similar to %w and %W).
* Default source encoding is changed to UTF-8. (was US-ASCII)
* No warning for unused variables starting with '_'
