Metadata Provider fixes & enhancements

[fcurdi]

Fix and add some missing features that came up when reading some libraries dlls. This Pull Request several features and changes because they were dependant on each other.

• Include Properties:
  • Model based on Added model for property definitions. #27. The only difference in the model is the IsStatic field that was missing and is needed to generate properties.
• Include Generic Parameter Constraints:
  • Based on Added Constraints set to GenericParameter class. #17. Added the Variance and default constructor info that was missing and is needed for generation.
• Move FakeArrayType to Types since it is needed to know if a type is of this type. Also renamed it to ArrayTypeWrapper.
• Move some utility MethodDefinition methods to Extensions so they can be used by references as well.
• Add Version, Culture and PublicKey to IAssemblyReference.
• Include a method reference to CreateArrayInstruction
  • Some arrays like multidimensional ones are created with the newobj instruction that needs a method reference to its constructor.
• Include method reference to StoreArrayElementInstruction and LoadArrayElementInstruction
  • This instructions are method calls in the bytecode and also need a method reference.
• Some fields like ContainingAssembly, ContainingNamespace and generic parameters were being set in the ExtractType/Method/etc() method and now they are set in the GetDefinedType/Method/etc() methods. This is because this info is sometimes needed before the ExtractType/Method/etc() is called (with references for example).
• Add OverridenMethod to MethodDefinition.
  • This points to the method that is being overriden.
  • It is needed for method generation.
• Add Custom attributes