-improved WASM compilation scripts

-added external bindbc.sdl import for WASM
-working on demos (WIP, working simple demo with ECS and SDL2)
-small change in ecs.std

demos/utils/dub.json

@@ -0,0 +1,50 @@
+{
+	"name": "ecs_utils",
+	"authors": [
+		"Michał Masiukiewicz", "Dawid Masiukiewicz"
+	],
+	"description": "Dynamic Entity Component System examples utils",
+	"copyright": "Copyright © 2018-2019, Michał Masiukiewicz, Dawid Masiukiewicz",
+	"license": "BSD",
+	"sourcePaths" : [
+		"source\/"
+	],
+	"importPaths": [
+		"source"
+	],
+	"dflags-posix-ldc": [
+		"-defaultlib=phobos2-ldc,druntime-ldc"
+	],
+	"dflagss": [
+		"-betterC"
+	],
+	"dependencies": {
+		"bindbc-sdl":"0.10.1"
+	},
+	"versions": [
+		"BindSDL_Image",
+		"SDL_2010"
+	],
+	
+	"configurations" : [
+		{
+			"name" : "default",
+			"targetType" : "library",
+			"subConfigurations": 
+			{
+				"bindbc-sdl": "static"	
+			}
+		},
+		{
+			"name" : "betterC",
+			"targetType" : "library",
+			"dflags": [
+				"-betterC"
+			],
+			"subConfigurations": 
+			{
+				"bindbc-sdl": "staticBC"	
+			}
+		}
+	]
+}