Constant for language name and several usage for this constant

compiler/frontend/src/org/jetbrains/jet/plugin/JetFileType.java

@@ -43,13 +43,13 @@ public class JetFileType extends LanguageFileType {
     @Override
     @NotNull
     public String getName() {
-        return "Kotlin";
+        return JetLanguage.NAME;
     }
 
     @Override
     @NotNull
     public String getDescription() {
-        return "Kotlin";
+        return getName();
     }
 
     @Override

compiler/frontend/src/org/jetbrains/jet/plugin/JetLanguage.java

@@ -23,8 +23,14 @@ import com.intellij.lang.Language;
 
 public class JetLanguage extends Language {
     public static JetLanguage INSTANCE = new JetLanguage();
+    public static String NAME = "Kotlin";
 
     private JetLanguage() {
         super("jet");
     }
+
+    @Override
+    public String getDisplayName() {
+        return NAME;
+    }
 }