The files react/index.native.js and react/index.web.js ended up having
very similar source code related to initializing the Redux store. Remove
the duplication.

Additionally, I always wanted the App React Component to be consumed
without the need to provide a Redux store to it.

A bug was discovered in d17cc9fa which would raise a failure to push
into the browser's history if a base href was defined. Fix the failure
by removing react-router. Anyway, the usage of react-router was
incorrect because the app must hit the server infrastructure when it
enters a room because the server will choose the very app version then.

As an intermediate step on the path to merging jitsi-meet and
jitsi-meet-react, import the whole source code of jitsi-meet-react as it
stands at
2f23d98424
i.e. the lastest master at the time of this import. No modifications are
applied to the imported source code in order to preserve a complete
snapshot of it in the repository of jitsi-meet and, thus, facilitate
comparison later on. Consequently, the source code of jitsi-meet and/or
jitsi-meet-react may not work. For example, jitsi-meet's jshint may be
unable to parse jitsi-meet-react's source code.