Implemented rendering parameter injection into the GlassViewModel

[smithc]

Resolves issue #9

Rendering parameters templates may now be injected and used in a strongly-typed manner with GlassViewModels:

public class MyViewModel : GlassViewModel<IGlassBase, IRenderingTemplate> {

    // The constructor params are optional... only if you need to use them
    public MyViewModel(IGlassBase datasource, IRenderingTempalate renderingParams) 
    {
        ...
    }

}