sky/shell should link with sky/engine

sky/engine/core/html/HTMLAnchorElement.cpp

Index: sky/engine/core/html/HTMLAnchorElement.cpp
diff --git a/sky/engine/core/html/HTMLAnchorElement.cpp b/sky/engine/core/html/HTMLAnchorElement.cpp
index 6b0ee928f90eb60929ef1b3aa600f079d742e871..e7917b18ef0caec58805878bb1b9a0b9c0fa788f 100644
--- a/sky/engine/core/html/HTMLAnchorElement.cpp
+++ b/sky/engine/core/html/HTMLAnchorElement.cpp
@@ -117,7 +117,7 @@ void HTMLAnchorElement::handleClick(Event* event)
         return;
     mojo::URLRequestPtr request = mojo::URLRequest::New();
     request->url = href().string().toUTF8();
-    host->services().NavigatorHost()->RequestNavigate(
+    host->services()->NavigatorHost()->RequestNavigate(

[eseidel, 2015/02/04 08:23:58]

Servics can be null now, do you want to crash here?

[abarth-chromium, 2015/02/04 16:40:05]

I think that's ok for now.  We'll probably need to do something smarter at some
point.

         mojo::TARGET_SOURCE_NODE, request.Pass());
     event->setDefaultHandled();
 }