-fixed crash on getComponent when component doesn't exist

-fixed Components ids sorting
-added deferred object removing
-new EntityManager functions: begin(), end().

source/ecs/manager.d

@@ -1,22 +1,23 @@
 module ecs.manager;
 
-import std.experimental.allocator.mallocator : Mallocator, AlignedMallocator;
-import std.experimental.allocator;
-import std.traits;
 import std.algorithm : max;
 import std.conv : to;
+import std.experimental.allocator;
+import std.experimental.allocator.mallocator : AlignedMallocator, Mallocator;
+import std.traits;
 
-import core.stdc.string;
 import core.stdc.stdlib;
+import core.stdc.string;
 
-import ecs.system;
 import ecs.entity;
-import ecs.vector;
+import ecs.entity_allocator;
 import ecs.hash_map;
 import ecs.id_manager;
-import ecs.entity_allocator;
+import ecs.system;
+import ecs.vector;
 
 alias gEM = EntityManager.instance;
+alias SerializeVector = ecs.vector.Vector!ubyte;
 
 class EntityManager
 {
@@ -410,7 +411,7 @@ class EntityManager
         {
             ushort min = new_ids[i];
             int pos = i;
-            foreach(int j;0..new_ids.length)
+            foreach(int j;i..new_ids.length)
             {
                 if(new_ids[j] < min)
                 {
@@ -562,6 +563,11 @@ class EntityManager
     }
 
     void removeEntity(EntityID id)
+    {
+        entities_to_remove.add(id);
+    }
+
+    void __removeEntity(EntityID id)
     {
         //get entity and block meta data pointers
         Entity* entity = id_manager.getEntityPointer(id);
@@ -571,7 +577,6 @@ class EntityManager
         id_manager.releaseID(id); //release id from manager
 
         removeEntityNoID(entity, block, true);
-
     }
 
     private void removeEntityNoID(Entity* entity, EntitiesBlock* block,
@@ -624,6 +629,25 @@ class EntityManager
         return cast(EntitiesBlock*)(cast(size_t) pointer & (~cast(size_t)(page_size - 1)));
     }
 
+    void removeEntites()
+    {
+        foreach(id;entities_to_remove)
+        {
+            __removeEntity(id);
+        }
+        entities_to_remove.clear();
+    }
+
+    void begin()
+    {
+        
+    }
+
+    void end()
+    {
+        removeEntites();
+    }
+
     struct ComponentInfo
     {
         ushort size;
@@ -710,6 +734,8 @@ class EntityManager
     IDManager id_manager;
     EntityAllocator allocator;
 
+    Vector!EntityID entities_to_remove;
+
     HashMap!(ushort[], EntityInfo*) entities_infos;
     HashMap!(string, uint) components_map;
     Vector!System systems;