Add @DeprecatedConfigurationProperties annotation

Add a new @DeprecatedConfigurationProperties annotation which can be
used by the `ConfigurationMetadataAnnotationProcessor` to generating
meta-data deprecated blocks.

Fixes gh-3543

spring-boot/src/main/java/org/springframework/boot/context/properties/DeprecatedConfigurationProperty.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2012-2015 the original author or authors.
+ *
+ * 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 org.springframework.boot.context.properties;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Indicates that a getter in a {@link ConfigurationProperties} object is deprecated. This
+ * annotation has no bearing on the actual binding processes, but it is used by the
+ * {@code spring-boot-configuration-processor} to add deprecation meta-data.
+ * <p>
+ * This annotation <strong>must</strong> be used on the getter of the deprecated element.
+ *
+ * @author Phillip Webb
+ * @since 1.3.0
+ */
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface DeprecatedConfigurationProperty {
+
+	/**
+	 * The reason for the deprecation.
+	 * @return the deprecation reason
+	 */
+	String reason() default "";
+
+	/**
+	 * The field that should be used instead (if any).
+	 * @return the replacement field
+	 */
+	String replacement() default "";
+
+}