Common update:

-added multiple new function to allocate template and add entity
-updated README.md (complete initial version)
-empty components now don't take memory
-fixedd small bug with TestRunner
-added many new tests (HashMap, Vector, EntityMeta, ...)
-added default hashing function to HashMap
-fixed critical bug with adding entities
-fixed small bug with adding entity with remplacement components
-added asserts into code to better bug detection
-small performance improvement for events
-added ComponentRef structure which contain data pointer and componentID
-remove EntityID from Event structure
-now events are handled before removing entiteis
-fixed GDC compilation
-fixed rendering of rotated sprites
-added weapons as separate entities to space ship and others
-added Tower enemy to SpaceInvaders demo
-added Boss to SpaceInvaders demo (boss has four tower attached to it)
-Boss towers shoot multiple bullets upon death
-fixed critical bug with demos switching
-fixed critical bug related to adding/removing entities form inside onAdd/onRemove entity callback
-added animation support
-added particles sypport and particles for firing and explostions, and more
-multithreaded rendering now has same rendering order as singlethreaded
-application automaticallu detect host CPU threads count
-added upgrades to SPaceInvaders demo
-fixed texture memory freeing
-improved documentation
-improved multithreaded performance
-improve shader code
-fixed registration issue
-some additional performance improvements
-added depth and colors to rendering parameters
-jobs now has names corresponding to their systems
-change execute() -> willExecute()
-added EntityMeta structure to speedup getting fetching components form entity
-improved multithreading rendering
-added possibility tio change number of threads runtime
-added bullets collision detection in SpaceInvaders demo
-some CI changes
-added VBO batch rendering (current default, no render mode switch yet)
-fixed camera positioning calculation
-fixed buffer issue with WebGL
-added viewport scalling (at least 300 pixels height). Pixels are scalled if screen is bigger.
-center demos gameplay area
-added fullpage html template for Emscripten build
-added many new sprites to atlas
-fixed critical bug with CPU usage in multithreaded mode
-snake render tile coresponding to body part
-snake is destroyed after collision and emit some particles
-added some functionality to vectors
-fixed documentation issue in Manager.d
-more minor code changes and cleanup

source/ecs/attributes.d

@@ -1,28 +0,0 @@
-/************************************************************************************************************************
-This module contain attributes used to mark components.
-Currently only two attributes are supported:
-$(LIST
-    * optional: mark component as optional for system update
-    * readonly: mark component access as read only (used for multithreading)
-)
-
-By default components are required and mutable. "const" attribute can be used insteac od readonly mark.
-
----
-Struct EntitiesData
-{
-   Comp1[] cmp; //mutable required component
-   @readonly @optional Comp2[] cmp2; //optional read only component
-   @optional const (Comp3)[] cmp3; //same as cmp2
-}
----
-
-Copyright: Copyright © 2018-2019, Dawid Masiukiewicz, Michał Masiukiewicz
-License: BSD 3-clause, see LICENSE file in project root folder.
-*/
-module ecs.attributes;
-
-///Used to mark optional components for system.
-enum optional = "optional";
-///Used to mark readonly components for system. "const" can be used insted.
-enum readonly = "readonly";