Added support for constructor injection

Author: ti24horas

Bson/Serialization/BsonClassMap.cs

@@ -886,7 +886,16 @@ public void SetExtraElementsMember(BsonMemberMap memberMap)
 
             _extraElementsMemberMap = memberMap;
         }
+        /// <summary>
+        /// Sets the constructor for the object
+        /// </summary>
+        /// <param name="constructor"></param>
+        public BsonClassMap SetConstructor(Func<object> constructor)
+        {
+            this._creator = constructor;
+            return this;
 
+        }
         /// <summary>
         /// Sets the Id member.
         /// </summary>
@@ -1384,6 +1393,8 @@ public BsonMemberMap GetMemberMap<TMember>(Expression<Func<TClass, TMember>> mem
             return GetMemberMap(memberName);
         }
 
+        
+
         /// <summary>
         /// Creates a member map for the extra elements field and adds it to the class map.
         /// </summary>