* large WARC loading optimizations (attempted to fix #67)

- use dedicated web worker for loading, remove when done
- update to warcio 1.5.0 for faster loading of large WARCs
- show WARC records loading for better progress update

* fidelity: fix potentially invalid location redirect via wombat 3.3.5 (see: webrecorder/pywb#684)

* dependencies: wabac.js 2.10.0-beta.0 (includes warcio 1.5.0, wombat 3.3.5)

* bump to 1.5.6, update CHANGES

webpack.config.js

@@ -31,6 +31,7 @@ const fallback = {
   "querystring": require.resolve("querystring-es3"),
   "url": require.resolve("url/"),
   "buffer": false,
+  "process": false
 };
 
 const optimization = {