Actually add the dialog

src/components/views/dialogs/CryptoStoreTooNewDialog.js

@@ -0,0 +1,71 @@
+/*
+Copyright 2018 New Vector Ltd
+
+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.
+*/
+
+import React from 'react';
+import sdk from '../../../index';
+import dis from '../../../dispatcher';
+import { _t } from '../../../languageHandler';
+import Modal from '../../../Modal';
+
+export default (props) => {
+    const _onLogoutClicked = () => {
+        const QuestionDialog = sdk.getComponent("dialogs.QuestionDialog");
+        Modal.createTrackedDialog('Logout e2e db too new', '', QuestionDialog, {
+            title: _t("Sign out"),
+            description: _t(
+                "To avoid losing your chat history, you must export your room keys " +
+                "before logging out. You will need to go back to the newer version of " +
+                "Riot to do this",
+            ),
+            button: _t("Sign out"),
+            focus: false,
+            onFinished: (doLogout) => {
+                if (doLogout) {
+                    dis.dispatch({action: 'logout'});
+                    props.onFinished();
+                }
+            },
+        });
+    };
+
+    const description =
+        _t("You've previously used a newer version of Riot on %(host)s. " +
+            "To use this version again with end to end encryption, you will " +
+            "need to sign out and back in again. ",
+            {host: props.host},
+        );
+
+    const BaseDialog = sdk.getComponent('views.dialogs.BaseDialog');
+    const DialogButtons = sdk.getComponent('views.elements.DialogButtons');
+    return (<BaseDialog className="mx_CryptoStoreTooNewDialog"
+        contentId='mx_Dialog_content'
+        title={_t("Incompatible Database")}
+        hasCancel={false}
+        onFinished={props.onFinished}
+    >
+        <div className="mx_Dialog_content" id='mx_Dialog_content'>
+            { description }
+        </div>
+        <DialogButtons primaryButton={_t('Continue With Encryption Disabled')}
+            hasCancel={false}
+            onPrimaryButtonClick={props.onFinished}
+        >
+            <button onClick={_onLogoutClicked} >
+                { _t('Sign out') }
+            </button>
+        </DialogButtons>
+    </BaseDialog>);
+};