prefer type equality;

--- a/src/Tools/VSCode/extension/src/decorations.ts	Thu Mar 09 21:55:02 2017 +0100
+++ b/src/Tools/VSCode/extension/src/decorations.ts	Fri Mar 10 11:03:46 2017 +0100
@@ -145,7 +145,7 @@
     document_decorations.set(decoration.uri, document)
 
     for (const editor of vscode.window.visibleTextEditors) {
-      if (decoration.uri == editor.document.uri.toString()) {
+      if (decoration.uri === editor.document.uri.toString()) {
         editor.setDecorations(typ, decoration.content)
       }
     }

--- a/src/Tools/VSCode/extension/src/extension.ts	Thu Mar 09 21:55:02 2017 +0100
+++ b/src/Tools/VSCode/extension/src/extension.ts	Fri Mar 10 11:03:46 2017 +0100
@@ -17,9 +17,9 @@
   const isabelle_home = vscode.workspace.getConfiguration("isabelle").get<string>("home");
   const isabelle_args = vscode.workspace.getConfiguration("isabelle").get<Array<string>>("args");
 
-  if (is_windows && cygwin_root == "")
+  if (is_windows && cygwin_root === "")
     vscode.window.showErrorMessage("Missing user settings: isabelle.cygwin_root")
-  else if (isabelle_home == "")
+  else if (isabelle_home === "")
     vscode.window.showErrorMessage("Missing user settings: isabelle.home")
   else {
     const isabelle_tool = isabelle_home + "/bin/isabelle"