update to latest wabac.js -- fix reading small wacz files

embed fixes: fix 'replayonly' mode to hide locationbar
embed loading screen: simplify, don't show cancel button, filename
bump to electron 10.0.0
bump to beta.1

webpack.config.js

@@ -103,13 +103,9 @@ const browserConfig = (env, argv) => {
         test:  /\.svg$/,
         loader: 'svg-inline-loader'
       },
-      {
-        test: /base.scss$/,
-        loaders: [MiniCssExtractPlugin.loader, 'css-loader', 'sass-loader']
-      },
       {
         test: /main.scss$/,
-        loaders: ['to-string-loader', 'css-loader', 'sass-loader']
+        loaders: ['css-loader', 'sass-loader']
       },
       {
         test: /wombat.js|wombatWorkers.js|index.html$/i,