Add basic AllocationToken validation/redemption for domain creates

The next step is to add them for domain checks as well (which is simpler
because it doesn't involve validation).

This requires the addition of a TrimWhitespaceAdapter for XML JAXB objects,
which will prove useful for other @XmlValue attributes in the future.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=181526726

javatests/google/registry/xml/TrimWhitespaceAdapterTest.java

@@ -0,0 +1,45 @@
+// Copyright 2017 The Nomulus Authors. All Rights Reserved.
+//
+// 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 google.registry.xml;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link TrimWhitespaceAdapter}. */
+@RunWith(JUnit4.class)
+public class TrimWhitespaceAdapterTest {
+
+  @Test
+  public void testUnmarshal() {
+    TrimWhitespaceAdapter adapter = new TrimWhitespaceAdapter();
+    assertThat(adapter.unmarshal("blah")).isEqualTo("blah");
+    assertThat(adapter.unmarshal("")).isEmpty();
+    assertThat(adapter.unmarshal(null)).isNull();
+    assertThat(adapter.unmarshal("\n    test foo bar   \n   \r")).isEqualTo("test foo bar");
+  }
+
+  @Test
+  public void testMarshal() {
+    TrimWhitespaceAdapter adapter = new TrimWhitespaceAdapter();
+    assertThat(adapter.marshal("blah")).isEqualTo("blah");
+    assertThat(adapter.marshal("")).isEmpty();
+    assertThat(adapter.marshal(null)).isNull();
+    assertThat(adapter.marshal("\n    test foo bar   \n   \r"))
+        .isEqualTo("\n    test foo bar   \n   \r");
+  }
+}