Reorganize some classes after CS1 was removed

Some of these were shared between CS1 and the unified screen or
CS2. Now that CS1 is gone the "changes" package is mostly about
listing one or more changes in dashboards or search results.

Move code to "patches" (for unified) or "change" (for CS2).

Change-Id: Ia87183e1e8d105ea3894bb426432b10153205a6f

gerrit-gwtui/src/main/java/com/google/gerrit/client/change/SubmitFailureDialog.java

@@ -0,0 +1,32 @@
+// Copyright (C) 2009 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.client.change;
+
+import com.google.gerrit.client.ErrorDialog;
+import com.google.gerrit.client.changes.Util;
+import com.google.gwtexpui.safehtml.client.SafeHtmlBuilder;
+import com.google.gwtjsonrpc.client.RemoteJsonException;
+
+class SubmitFailureDialog extends ErrorDialog {
+  static boolean isConflict(Throwable err) {
+    return err instanceof RemoteJsonException
+        && 409 == ((RemoteJsonException) err).getCode();
+  }
+
+  SubmitFailureDialog(String msg) {
+    super(new SafeHtmlBuilder().append(msg.trim()).wikify());
+    setText(Util.C.submitFailed());
+  }
+}