-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/external/imports/bindbc/sdl/bind/sdltouch.d

@@ -0,0 +1,67 @@
+
+//          Copyright Michael D. Parker 2018.
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE_1_0.txt or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
+
+module bindbc.sdl.bind.sdltouch;
+
+import bindbc.sdl.config;
+
+alias SDL_TouchID = long;
+alias SDL_FingerID = long;
+
+struct SDL_Finger {
+    SDL_FingerID id;
+    float x;
+    float y;
+    float pressure;
+}
+
+enum DL_TOUCH_MOUSEID = cast(uint)-1;
+
+static if(sdlSupport >= SDLSupport.sdl2010) {
+    enum SDL_TouchDeviceType {
+        SDL_TOUCH_DEVICE_INVALID = -1,
+        SDL_TOUCH_DEVICE_DIRECT,
+        SDL_TOUCH_DEVICE_INDIRECT_ABSOLUTE,
+        SDL_TOUCH_DEVICE_INDIRECT_RELATIVE,
+    }
+    mixin(expandEnum!SDL_TouchDeviceType);
+
+    enum SDL_MOUSE_TOUCHID = -1L;
+}
+
+version(BindSDL_Static) {
+    extern(C) @nogc nothrow {
+        int SDL_GetNumTouchDevices();
+        SDL_TouchID SDL_GetTouchDevice(int);
+        int SDL_GetNumTouchFingers(SDL_TouchID);
+        SDL_Finger* SDL_GetTouchFinger(SDL_TouchID,int);
+    }
+    static if(sdlSupport >= SDLSupport.sdl2010) {
+        SDL_TouchDeviceType SDL_GetTouchDeviceType(SDL_TouchID);
+    }
+}
+else {
+    extern(C) @nogc nothrow {
+        alias pSDL_GetNumTouchDevices = int function();
+        alias pSDL_GetTouchDevice = SDL_TouchID function(int);
+        alias pSDL_GetNumTouchFingers = int function(SDL_TouchID);
+        alias pSDL_GetTouchFinger = SDL_Finger* function(SDL_TouchID,int);
+    }
+    __gshared {
+        pSDL_GetNumTouchDevices SDL_GetNumTouchDevices;
+        pSDL_GetTouchDevice SDL_GetTouchDevice;
+        pSDL_GetNumTouchFingers SDL_GetNumTouchFingers;
+        pSDL_GetTouchFinger SDL_GetTouchFinger;
+    }
+    static if(sdlSupport >= SDLSupport.sdl2010) {
+        extern(C) @nogc nothrow {
+            alias pSDL_GetTouchDeviceType = SDL_TouchDeviceType function(SDL_TouchID);
+        }
+        __gshared {
+            pSDL_GetTouchDeviceType SDL_GetTouchDeviceType;
+        }
+    }
+}