Added PersistenceManager and Namedqueries

In theory, this code is all we need for database integration

src/main/java/envoy/server/data/User.java

@@ -7,6 +7,8 @@ import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
 import javax.persistence.Id;
+import javax.persistence.NamedQuery;
+import javax.persistence.Table;
 import javax.persistence.Temporal;
 import javax.persistence.TemporalType;
 
@@ -24,6 +26,8 @@ import javax.persistence.TemporalType;
  * @since Envoy Server Standalone v0.1-alpha
  */
 @Entity
+@Table(name = "users")
+@NamedQuery(query = "SELECT u FROM DBUser u WHERE u.id = :id", name = "getUserById")
 public class User {
 
 	@Id