new Ruby Binding sfml-ruby

[Hanmac]

Hi i made an new SFML binding that works with ruby Trunk and is a little bit different that  rbSFML
https://github.com/Hanmac/sfml-ruby

Some of the differents:

• Enum Values are mapped against Symbol, so you dont need the constants
• RenderTarget pointer are Stored inside a std::map to reuse them
• uses key arguments for the classes that inherit from Transformable

currently its not finish yet, and the audio is totaly missing but the Shader example does work as it should