Implement "Safe Delete" refactoring for named functions

Conflicts:
	idea/src/org/jetbrains/jet/plugin/refactoring/safeDelete/KotlinSafeDeleteProcessor.java

idea/testData/safeDelete/deleteJavaMethod/mixedHierarchy2.kt.after

@@ -0,0 +1,8 @@
+trait B: A {
+    public override fun foo() {
+        throw UnsupportedOperationException()
+    }
+}
+
+class D: C() {
+}