rename "Kotlin Trait" file template to "Kotlin Interface"

idea/resources/fileTemplates/internal/Kotlin Interface.kt.ft

@@ -2,5 +2,5 @@
 
 #end
 #parse("File Header.java")
-public trait ${NAME} {
+public interface ${NAME} {
 }

idea/resources/fileTemplates/internal/Kotlin Interface.kt.html

@@ -5,7 +5,7 @@
     <td colspan="3">
       <font face="verdana" size="-1">
         This is a built-in template used by <b>IDEA</b> each time you create a
-        Kotlin trait
+        Kotlin interface
       </font>
     </td>
   </tr>

idea/src/org/jetbrains/kotlin/idea/actions/NewKotlinFileAction.java

@@ -58,7 +58,7 @@ public class NewKotlinFileAction extends CreateFileFromTemplateAction implements
                 .setTitle(JetBundle.message("new.kotlin.file.action"))
                 .addKind("Kotlin file", JetFileType.INSTANCE.getIcon(), "Kotlin File")
                 .addKind("Class", JetIcons.CLASS, "Kotlin Class")
-                .addKind("Trait", JetIcons.TRAIT, "Kotlin Trait")
+                .addKind("Interface", JetIcons.TRAIT, "Kotlin Interface")
                 .addKind("Enum class", JetIcons.ENUM, "Kotlin Enum")
                 .addKind("Object", JetIcons.OBJECT, "Kotlin Object");
     }