Configuration:
- PDF.js version: 2.0.550

Steps to reproduce the problem:
1. Render document in SVG mode `renderMode="svg"`

What is the expected behavior? (add screenshot)
Rendering annotations same way as they rendered on canvas

What went wrong? (add screenshot)
```
Warning: Unimplemented operator beginAnnotations
Warning: Unimplemented operator endAnnotations
```
if (!isName(style)) {
      return;
    }
    switch (style.name) {
      case "S":
        this.style = AnnotationBorderStyleType.SOLID;
        break;
      case "D":
        this.style = AnnotationBorderStyleType.DASHED;
        break;
      case "B":
        this.style = AnnotationBorderStyleType.BEVELED;
        break;
      case "I":
        this.style = AnnotationBorderStyleType.INSET;
        break;
      case "U":
        this.style = AnnotationBorderStyleType.UNDERLINE;
        break;
      default:
        break;
    }
  }