Dropped MongoDB river functionality from ES

It was a prime suspect in frequent ES crashes case. Now index is managed from the app logic (/models/plugins/Search mainly).
Reindex search functionality

Drops all documents from ES and indexes them again.
Use res.status().send() in serve-response

res.send(status, body) is depreciated in express.
Options for urlencoded body parser and session

  * body-parser urlencoded extended
  * session resave
  * session saveUninitialized

Lack of those options in init is depreciated in this modules.
Use moment.locale instead of moment.lang

Later is depreciated.
Use enter key to submit search form

Also use search form component in search results view.
Populate single stories' questions with answers

To display it's count.