moved @Indexed to data-commons

spring-data-commons-core/src/main/java/org/springframework/datastore/annotation/Indexed.java

@@ -0,0 +1,12 @@
+package org.springframework.datastore.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface Indexed
+{
+}