Revert "Refactor frontend"

This reverts commit 1950cc8db0.

lib/document_handler.js

@@ -55,7 +55,7 @@ DocumentHandler.prototype.handlePost = function(request, response) {
     if (!buffer) {
       response.writeHead(200, { 'content-type': 'application/json' });
     }
-    buffer += JSON.parse(data.toString()).data;
+    buffer += data.toString();
     if (_this.maxLength && buffer.length > _this.maxLength) {
       cancelled = true;
       winston.warn('document >maxLength', { maxLength: _this.maxLength });