"trait" instead of "trait class"

virtual -> open
 "final" introduced
 "wraps" dropped

idea/testData/codegen/bridge.jet

@@ -1,7 +1,7 @@
 import java.lang.Integer
 
 open class C {
-    virtual fun f(): Any = "C f"
+    open fun f(): Any = "C f"
 }
 
 class D() : C {

idea/testData/codegen/classes/diamondInheritance.jet

@@ -5,7 +5,7 @@ open class Base() {
 }
 
 open class Left() : Base() {}
-trait class Right : Base {}
+trait Right : Base {}
 
 class D() : Left(), Right
 

idea/testData/codegen/classes/funDelegation.jet

@@ -2,7 +2,7 @@ open class Base() {
     fun n(n : Int) : Int = n + 1
 }
 
-trait class Abstract {}
+trait Abstract {}
 
 class Derived1() : Base(), Abstract {}
 class Derived2() : Abstract, Base() {}

idea/testData/codegen/classes/inheritance.jet

@@ -1,7 +1,7 @@
 // Changed when traits were introduced. May not make sense any more
 
 open class X(val x : Int) {}
-trait class Y {
+trait Y {
     abstract val y : Int
 }
 
@@ -11,7 +11,7 @@ class Point(x : Int, yy : Int) : X(x) , Y {
     override val y : Int = yy
 }
 
-trait class Abstract {}
+trait Abstract {}
 
 class P1(x : Int, yy : Y) : Abstract, X(x), Y by yy {}
 class P2(x : Int, yy : Y) : X(x), Abstract, Y by yy {}

idea/testData/codegen/classes/propertyDelegation.jet

@@ -10,7 +10,7 @@ open class Base() {
       }
 }
 
-trait class Abstract {}
+trait Abstract {}
 
 class Derived1() : Base(), Abstract {}
 class Derived2() : Abstract, Base() {}

idea/testData/codegen/classes/rightHandOverride.jet

@@ -1,8 +1,8 @@
 // Changed when traits were introduced. May not make sense any more
 
-trait class Left {}
+trait Left {}
 open class Right() {
-    virtual fun f() = 42
+    open fun f() = 42
 }
 
 class D() : Left, Right() {