Huge demos update

-moved C stdlib function definitions to ecs_utils.utils
-added function to calculate mix(linear interpolation) and rsqrt(fast inverse sqrt)
-added some math to vec2 (length, normalize...)
-improved renderer with possibility to use multiple materials (one per block, not perfect solution for parallel compute, but works with some requirements)
-added blending support for material (opaque, additive, mixed)
-added Android support
-added gprahical representation for mouse tools (tool_circle.d)
-added initial support for editing template components variables
-better Component and Templates listing
-added possibility to add/removes components using mouse
-move CLocation to game_core.basic and reuse in every test
-moved tools code from demos to App (now code is fully separated from demos!)
-some improvement and fixes in Snake demo, with additional systems to handle adding and removing entities
-added new demo: Particles. By now demo has several particles to spawn and support for attractors and vortexes (calculation is made as every attractor with every entity)
-fixed bug with window hover and tools
-improved tool behaviour
-added new material
-now window is always opened as maximized windowed mode
-some minor fixes and improvements

demos/utils/source/ecs_utils/gfx/buffer.d

@@ -68,7 +68,7 @@ struct Buffer
     void map(BindTarget target) nothrow
     {
         bind(target);
-        version(Android){}else data.map_ptr = glMapBuffer(target,GL_WRITE_ONLY);
+        version(Android){}else version(WebAssembly){}else data.map_ptr = glMapBuffer(target,GL_WRITE_ONLY);
     }
 
     void map(uint offset, uint size, BindTarget target, uint flags = MapFlagBits.write | MapFlagBits.flush_explict | MapFlagBits.invalidate_buffer) nothrow