Fix some more code analysis issues

src/GitHub.VisualStudio/Base/TeamExplorerNavigationItemBase.cs

@@ -128,8 +128,9 @@ namespace GitHub.VisualStudio
                 return;
 
             var solService = ServiceProvider.GetSolution();
-            var ret = solService.AdviseSolutionEvents(new SolutionEventListener(SolutionOpen), out cookie);
-            Debug.Assert(ErrorHandler.Succeeded(ret), "Unable to start listening for solution events");
+            if (!ErrorHandler.Succeeded(solService.AdviseSolutionEvents(new SolutionEventListener(SolutionOpen), out cookie))) {
+                Debug.Assert(false, "Unable to start listening for solution events");
+            }
         }
 
         void UnsubscribeSolutionEvents()
@@ -139,8 +140,9 @@ namespace GitHub.VisualStudio
                 return;
 
             var solService = ServiceProvider.GetSolution();
-            var ret = solService.UnadviseSolutionEvents(cookie);
-            Debug.Assert(ErrorHandler.Succeeded(ret), "Unable to stop listening for solution events");
+            if (!ErrorHandler.Succeeded(solService.UnadviseSolutionEvents(cookie))) {
+                Debug.Assert(false, "Unable to stop listening for solution events");
+            }
             cookie = 0;
         }
 

src/GitHub.VisualStudio/TeamExplorerHome/GraphsNavigationItem.cs

@@ -13,7 +13,7 @@ namespace GitHub.VisualStudio
     [TeamExplorerNavigationItem(GraphsNavigationItemId,
         NavigationItemPriority.Graphs,
         TargetPageId = TeamExplorerPageIds.Home)]
-    class GraphsNavigationItem : TeamExplorerNavigationItemBase
+    public class GraphsNavigationItem : TeamExplorerNavigationItemBase
     {
         public const string GraphsNavigationItemId = "5245767A-B657-4F8E-BFEE-F04159F1DDA5";
 

src/GitHub.VisualStudio/TeamExplorerHome/IssuesNavigationItem.cs

@@ -13,7 +13,7 @@ namespace GitHub.VisualStudio
     [TeamExplorerNavigationItem(IssuesNavigationItemId,
         NavigationItemPriority.Issues,
         TargetPageId = TeamExplorerPageIds.Home)]
-    class IssuesNavigationItem : TeamExplorerNavigationItemBase
+    public class IssuesNavigationItem : TeamExplorerNavigationItemBase
     {
         public const string IssuesNavigationItemId = "5245767A-B657-4F8E-BFEE-F04159F1DDA4";
 

src/GitHub.VisualStudio/TeamExplorerHome/PullRequestsNavigationItem.cs

@@ -13,7 +13,7 @@ namespace GitHub.VisualStudio
     [TeamExplorerNavigationItem(PullRequestsNavigationItemId,
         NavigationItemPriority.PullRequests,
         TargetPageId = TeamExplorerPageIds.Home)]
-    class PullRequestsNavigationItem : TeamExplorerNavigationItemBase
+    public class PullRequestsNavigationItem : TeamExplorerNavigationItemBase
     {
         public const string PullRequestsNavigationItemId = "5245767A-B657-4F8E-BFEE-F04159F1DDA3";
 

src/GitHub.VisualStudio/TeamExplorerHome/PulseNavigationItem.cs

@@ -13,7 +13,7 @@ namespace GitHub.VisualStudio
     [TeamExplorerNavigationItem(PulseNavigationItemId,
         NavigationItemPriority.Pulse,
         TargetPageId = TeamExplorerPageIds.Home)]
-    class PulseNavigationItem : TeamExplorerNavigationItemBase
+    public class PulseNavigationItem : TeamExplorerNavigationItemBase
     {
         public const string PulseNavigationItemId = "5245767A-B657-4F8E-BFEE-F04159F1DDA2";
 

src/GitHub.VisualStudio/TeamExplorerHome/WikiNavigationItem.cs

@@ -13,7 +13,7 @@ namespace GitHub.VisualStudio
     [TeamExplorerNavigationItem(WikiNavigationItemId,
         NavigationItemPriority.Wiki,
         TargetPageId = TeamExplorerPageIds.Home)]
-    class WikiNavigationItem : TeamExplorerNavigationItemBase
+    public class WikiNavigationItem : TeamExplorerNavigationItemBase
     {
         public const string WikiNavigationItemId = "5245767A-B657-4F8E-BFEE-F04159F1DDA1";