added proc support

Tests/Tests.cs

@@ -507,6 +507,30 @@ public void TestSupportForParamDictionary()
             p.Get<int>("@age").IsEqualTo(11);
         }
 
+
+        public void TestProcSupport()
+        {
+            var p = new DynamicParameters();
+            p.Add("@a", 11);
+            p.Add("@b", dbType: DbType.Int32, direction: ParameterDirection.Output);
+            p.Add("@c", dbType: DbType.Int32, direction: ParameterDirection.ReturnValue);
+
+            connection.Execute(@"create proc #TestProc 
+	@a int,
+	@b int output
+as 
+begin
+	set @b = 999
+	select 1111
+	return @a
+end");
+            connection.Query<int>("#TestProc", p, commandType: CommandType.StoredProcedure).First().IsEqualTo(1111);
+
+            p.Get<int>("@c").IsEqualTo(11);
+            p.Get<int>("@b").IsEqualTo(999);
+
+        }
+
         /* TODO:
          * 
         public void TestMagicParam()