DATACOUCH-71 - Add support for JSR 303 validation.

This changeset adds validation support for entities, and since this depends
on events, the event functionality has been added as well. Now also generic
event listeners can be attached.

pom.xml

@@ -21,6 +21,7 @@
     <couchbase>1.3.1</couchbase>
     <jackson>2.3.1</jackson>
     <springdata.commons>1.6.3.RELEASE</springdata.commons>
+    <validation>1.0.0.GA</validation>
   </properties>
 
   <dependencies>
@@ -74,6 +75,13 @@
       <scope>test</scope>
     </dependency>
 
+    <dependency>
+      <groupId>org.hibernate</groupId>
+      <artifactId>hibernate-validator</artifactId>
+      <version>4.2.0.Final</version>
+      <scope>test</scope>
+    </dependency>
+
     <dependency>
       <groupId>org.apache.httpcomponents</groupId>
       <artifactId>httpclient</artifactId>
@@ -94,6 +102,14 @@
       <optional>true</optional>
     </dependency>
 
+    <!-- JSR 303 Validation -->
+    <dependency>
+      <groupId>javax.validation</groupId>
+      <artifactId>validation-api</artifactId>
+      <version>${validation}</version>
+      <optional>true</optional>
+    </dependency>
+
     <dependency>
         <groupId>org.hamcrest</groupId>
         <artifactId>hamcrest-all</artifactId>