Added SimpleInjector container integration (only for >=.NET 4.0).

See https://github.com/maartenba/MvcSiteMapProvider/issues/102#issuecomment-19976825

Remarks :
- I could'nt follow registration conventions for default interfaces because SimpleInjector's RegisterAll() method requires all implementations for a given interface to be set at once (not successive calls).
- The version of SimpleInjector (v.2+) is available from .NET 4.0+.

Please let me know if something is wrong...