-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/config.d

@@ -0,0 +1,44 @@
+
+//          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.config;
+
+enum SDLSupport {
+    noLibrary,
+    badLibrary,
+    sdl200      = 200,
+    sdl201      = 201,
+    sdl202      = 202,
+    sdl203      = 203,
+    sdl204      = 204,
+    sdl205      = 205,
+    sdl206      = 206,
+    sdl207      = 207,
+    sdl208      = 208,
+    sdl209      = 209,
+    sdl2010      = 2010,
+}
+
+version(SDL_2010) enum sdlSupport = SDLSupport.sdl2010;
+else version(SDL_209) enum sdlSupport = SDLSupport.sdl209;
+else version(SDL_208) enum sdlSupport = SDLSupport.sdl208;
+else version(SDL_207) enum sdlSupport = SDLSupport.sdl207;
+else version(SDL_206) enum sdlSupport = SDLSupport.sdl206;
+else version(SDL_205) enum sdlSupport = SDLSupport.sdl205;
+else version(SDL_204) enum sdlSupport = SDLSupport.sdl204;
+else version(SDL_203) enum sdlSupport = SDLSupport.sdl203;
+else version(SDL_202) enum sdlSupport = SDLSupport.sdl202;
+else version(SDL_201) enum sdlSupport = SDLSupport.sdl201;
+else enum sdlSupport = SDLSupport.sdl200;
+
+enum expandEnum(EnumType, string fqnEnumType = EnumType.stringof) = (){
+    string expandEnum = "enum {";
+    foreach(m;__traits(allMembers, EnumType)) {
+        expandEnum ~= m ~ " = " ~ fqnEnumType ~ "." ~ m ~ ",";
+    }
+    expandEnum  ~= "}";
+    return expandEnum;
+}();