Improve code structure of the annotation code

This patch improves the code structure of the annotation code.

- Create the annotation border style object in the `setBorderStyle` method instead of in the constructor. The behavior is the same as the `setBorderStyle` method is always called, thus a border style object is still always available.
- Put all data object manipulation lines in one block in the constructor. This improves readability and maintainability as it is more visible which properties are exposed.
- Simplify `appendToOperatorList` by removing the promise capability and removing an unused parameter.
- Remove some unnecessary newlines/spaces.

src/core/core.js

@@ -210,7 +210,7 @@ var Page = (function PageClosure() {
         }
 
         var annotationsReadyPromise = Annotation.appendToOperatorList(
-          annotations, pageOpList, pdfManager, partialEvaluator, task, intent);
+          annotations, pageOpList, partialEvaluator, task, intent);
         return annotationsReadyPromise.then(function () {
           pageOpList.flush(true);
           return pageOpList;