Allow Texture Name In Sampler Using Parenthesis

We now support both:

```
samplerCUBE SkyBoxSampler = sampler_state 
{ 
   texture = (SkyBoxTexture); 
}
```

and

```
samplerCUBE SkyBoxSampler = sampler_state 
{ 
   texture = <SkyBoxTexture>; 
}
```

This is based on #1474, but it changes the input parser file and uses the parser generator.