Render native emoji with image fallback

Fix #779

src/core/config.js

@@ -21,6 +21,7 @@ export default function (vm) {
       nameLink: window.location.pathname,
       autoHeader: false,
       executeScript: null,
+      nativeEmoji: true,
       noEmoji: false,
       ga: '',
       ext: '.md',

src/core/render/compiler.js

@@ -104,7 +104,7 @@ export class Compiler {
           html = compile.parser(text);
         }
 
-        html = config.noEmoji ? html : emojify(html);
+        html = config.noEmoji ? html : emojify(html, config.nativeEmoji);
         slugify.clear();
 
         return html;