-better compile time code generation

-support for AbsenComponents. Absen components can't exist in entity which are
	used by system. There are three possibilities to add absen component. Add
	'@absen' property to EntitiesData mebmer, create AbsenComponents enum with fields
	names corresponding to components names, or create AbsenComponents AliasSeq
	with strings expressions corresponding to components names.

tests/tests.d

@@ -131,7 +131,7 @@ int main()
 			TestComp[] test;
 			TestComp2[] test2;
 			@optional TestComp3[] test3;
-			@absen TestComp4[] test4;
+			//@absen TestComp4[] test4;
 		}
 
 		void update(ref Entity entity, ref TestComp test, ref TestComp2 test2)//, TestComp3* test3) //ref TestComp comp)
@@ -188,15 +188,28 @@ int main()
 		}*/
 	}
 
+import std.meta;
+
 	struct TestSystem2
 	{
 		__gshared ushort system_id;
 
+		enum AbsenComponents0
+		{
+			TestComp,
+			TestComp4
+		}
+
+		alias AbsenComponents = AliasSeq!("TestComp", "TestComp4");
+
+		string AbsenComponents2;
+
 		static struct EntitiesData
 		{
 			short length;
 			Entity[] entity;
 			TestComp3[] test;
+			//@absen TestComp[] testt;
 		}
 
 		void onEnable()
@@ -225,7 +238,15 @@ int main()
 				data.test[i].gg += 14;
 				gEM.sendSelfEvent!(TestEvent)(data.entity[i].id, TestEvent());
 			}
-			
+		}
+		
+		void lateUpdate(ref EntitiesData data)
+		{
+			foreach(i;0..data.test.length)
+			{
+				data.test[i].gg -= 1;
+				gEM.sendSelfEvent!(TestEvent)(data.entity[i].id, TestEvent());
+			}
 		}
 
 		/*void handleEvent(Event event, ref TestComp comp)