Fixed DropShadow issue in NavigatorWindowStyle & added multi view edit to the CodeEditor

*I certify that I own, and have sufficient rights to contribute, all source code and related material intended to be compiled or integrated with the source code for the #develop open source product (the "Contribution"). My Contribution is licensed under the MIT License.*

Fixed an issue with the DropShadowEffect in the NavigatorWindowStyle of
AvalonDock.

***Before***
![sd_before_window](https://cloud.githubusercontent.com/assets/1153480/4295327/d5625f2a-3de8-11e4-8d42-d66b2e1badf5.png)



***After***
![After](https://cloud.githubusercontent.com/assets/1153480/4295324/c5128b72-3de8-11e4-976b-1a8f39e33f99.png)



Tweaked the the right margin for membersComboBox of the QuickClassBrowser.

Before | After
----------|-------
![margin_before](https://cloud.githubusercontent.com/assets/1153480/4353543/8bfaf824-4234-11e4-870d-f17e4bc71f5f.png)
|
![margin_after](https://cloud.githubusercontent.com/assets/1153480/4353546/90eb9ffa-4234-11e4-8e69-c5b99424c4dd.png)


Added multi view edit to the to the code editor, ***For this one I need more help for better integration because I don't understand everything around Avalond Editor***

![editor_multiview](https://cloud.githubusercontent.com/assets/1153480/4353556/b93c973e-4234-11e4-8660-925c371bdedb.png)